diff --git a/bazel/rules/rules_score/examples/seooc/design/dynamic_design.puml b/bazel/rules/rules_score/examples/seooc/design/dynamic_design.puml
index 5fe8e442..4d364ecd 100644
--- a/bazel/rules/rules_score/examples/seooc/design/dynamic_design.puml
+++ b/bazel/rules/rules_score/examples/seooc/design/dynamic_design.puml
@@ -13,8 +13,8 @@
 
 @startuml
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "Unit 1 : safety_software_seooc_example::component_example::unit_1" as unit_1 <<unit>>
+participant "Unit 2 : safety_software_seooc_example::component_example::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : GetData()
 return Data*
diff --git a/bazel/rules/rules_score/examples/seooc/design/public_api.puml b/bazel/rules/rules_score/examples/seooc/design/public_api.puml
index 61818294..760db8e3 100644
--- a/bazel/rules/rules_score/examples/seooc/design/public_api.puml
+++ b/bazel/rules/rules_score/examples/seooc/design/public_api.puml
@@ -13,10 +13,8 @@
 
 @startuml
 
-namespace safety_software_seooc_example {
-    interface "SampleLibraryAPI" as SampleLibraryAPI {
-        + GetNumber(): int
-    }
+interface "SampleLibraryAPI" as SampleLibraryAPI <<interface>> {
+    + GetNumber(): int
 }
 
 @enduml
diff --git a/bazel/rules/rules_score/examples/seooc/design/static_design.puml b/bazel/rules/rules_score/examples/seooc/design/static_design.puml
index 1bb80210..ef85542f 100644
--- a/bazel/rules/rules_score/examples/seooc/design/static_design.puml
+++ b/bazel/rules/rules_score/examples/seooc/design/static_design.puml
@@ -21,7 +21,7 @@ package "Safety Software SEooC Example" as safety_software_seooc_example <<SEooC
 
         interface "InternalInterface" as InternalInterface
         unit_1 -l-( InternalInterface
-        unit_2 -r- InternalInterface
+        unit_2 )-r- InternalInterface
     }
 }
 
diff --git a/bazel/rules/rules_score/examples/seooc/safety_analysis/sample_fmea_failure_modes.trlc b/bazel/rules/rules_score/examples/seooc/safety_analysis/sample_fmea_failure_modes.trlc
index 627258f9..2f5bee25 100644
--- a/bazel/rules/rules_score/examples/seooc/safety_analysis/sample_fmea_failure_modes.trlc
+++ b/bazel/rules/rules_score/examples/seooc/safety_analysis/sample_fmea_failure_modes.trlc
@@ -20,7 +20,7 @@ ScoreReq.FailureMode SampleFailureMode{
     failureeffect = "The world as we know it will end"
     version = 1
     safety = ScoreReq.Asil.B
-    interface = "safety_software_seooc_example.SampleLibraryAPI.GetNumber"
+    interface = "design.SampleLibraryAPI.GetNumber"
 }
 
 ScoreReq.FailureMode SampleFailureMode2{
@@ -29,5 +29,5 @@ ScoreReq.FailureMode SampleFailureMode2{
     failureeffect = "Downstream consumers time out"
     version = 1
     safety = ScoreReq.Asil.D
-    interface = "safety_software_seooc_example.SampleLibraryAPI.GetNumber"
+    interface = "design.SampleLibraryAPI.GetNumber"
 }
diff --git a/bazel/rules/rules_score/private/architectural_design.bzl b/bazel/rules/rules_score/private/architectural_design.bzl
index 807c9fec..68f47bef 100644
--- a/bazel/rules/rules_score/private/architectural_design.bzl
+++ b/bazel/rules/rules_score/private/architectural_design.bzl
@@ -24,7 +24,7 @@ to produce FlatBuffers binary representations of the parsed diagrams.
 
 load("@bazel_skylib//lib:paths.bzl", "paths")
 load("//bazel/rules/rules_score:providers.bzl", "ArchitecturalDesignInfo", "SphinxSourcesInfo")
-load("//bazel/rules/rules_score/private:puml_utils.bzl", "emit_view_navigation", "plan_view_layout", "relative_source_path")
+load("//bazel/rules/rules_score/private:puml_utils.bzl", "emit_view_navigation", "package_root_anchor", "plan_view_layout", "relative_source_path")
 load("//bazel/rules/rules_score/private:validation.bzl", "PROFILES", "VALIDATION_ATTRS", "run_validation")
 load("//bazel/rules/rules_score/private:verbosity.bzl", "VERBOSITY_ATTR", "get_log_level")
 load("//bazel/rules/rules_score/private:views.bzl", "ARCH_VIEWS")
@@ -138,6 +138,8 @@ def _run_puml_parser(ctx, puml_file, file_stem):
             puml_file.short_path,
             "--output-stem",
             file_stem,
+            "--root-anchor",
+            package_root_anchor(ctx),
             "--log-level",
             get_log_level(ctx),
         ],
diff --git a/bazel/rules/rules_score/private/puml_utils.bzl b/bazel/rules/rules_score/private/puml_utils.bzl
index f59fb484..666bb079 100644
--- a/bazel/rules/rules_score/private/puml_utils.bzl
+++ b/bazel/rules/rules_score/private/puml_utils.bzl
@@ -16,6 +16,21 @@ indexes for one architectural design view (static/dynamic/public_api/internal_ap
 
 load("@bazel_skylib//lib:paths.bzl", "paths")
 
+def package_root_anchor(ctx):
+    """Return the resolver root anchor derived from the owning Bazel package.
+
+    The resolver uid model uses dot-separated package segments, while Bazel
+    labels use `/` between package path elements.
+
+    Args:
+        ctx: Rule context.
+
+    Returns:
+        Dot-separated package path string, or the empty string for repo-root
+        targets.
+    """
+    return ctx.label.package.replace("/", ".")
+
 def relative_source_path(file, package, own_repo = None):
     """Return `file`'s path relative to `package`, or its full workspace-relative
     short_path when it doesn't live under `package` -- never just the bare
diff --git a/bazel/rules/rules_score/private/unit.bzl b/bazel/rules/rules_score/private/unit.bzl
index fcfb465f..dd2cc5b9 100644
--- a/bazel/rules/rules_score/private/unit.bzl
+++ b/bazel/rules/rules_score/private/unit.bzl
@@ -26,6 +26,7 @@ load("@rules_rust//rust:defs.bzl", "rust_common")
 load("//bazel/rules/rules_score:providers.bzl", "CcDependencyInfo", "CertifiedScope", "SphinxSourcesInfo", "UnitDesignInfo", "UnitInfo")
 load("//cpp/libclang:cpp_parser.bzl", "cpp_parser_action_internal_attrs", "cpp_parser_action_toolchains", "cpp_parser_target_aspects", "has_cpp_parser_inputs", "run_cpp_parser_action")
 load(":cc_dependency_aspect.bzl", "cc_dependencies_aspect")
+load(":puml_utils.bzl", "package_root_anchor")
 load(":validation.bzl", "PROFILES", "VALIDATION_ATTRS", "run_validation")
 load(":verbosity.bzl", "VERBOSITY_ATTR", "get_log_level")
 
@@ -36,6 +37,7 @@ def _run_implementation_cpp_parser(ctx, impl, output_prefix):
         output_prefix = output_prefix,
         tool = ctx.attr._tool,
         log_level = ctx.attr._log_level[BuildSettingInfo].value,
+        root_anchor = package_root_anchor(ctx),
     )
 
 def _target_output_prefix(ctx, target):
diff --git a/bazel/rules/rules_score/private/unit_design.bzl b/bazel/rules/rules_score/private/unit_design.bzl
index 5a5f2642..ecc018a0 100644
--- a/bazel/rules/rules_score/private/unit_design.bzl
+++ b/bazel/rules/rules_score/private/unit_design.bzl
@@ -25,6 +25,7 @@ verification tooling.
 """
 
 load("//bazel/rules/rules_score:providers.bzl", "SphinxSourcesInfo", "UnitDesignInfo")
+load("//bazel/rules/rules_score/private:puml_utils.bzl", "package_root_anchor")
 load("//bazel/rules/rules_score/private:verbosity.bzl", "VERBOSITY_ATTR", "get_log_level")
 
 # ============================================================================
@@ -68,6 +69,8 @@ def _run_puml_parser(ctx, puml_file):
             idmap_output.dirname,
             "--source-name",
             puml_file.short_path,
+            "--root-anchor",
+            package_root_anchor(ctx),
             "--log-level",
             get_log_level(ctx),
         ],
diff --git a/cpp/libclang/cpp_parser.bzl b/cpp/libclang/cpp_parser.bzl
index d4b54572..5328b073 100644
--- a/cpp/libclang/cpp_parser.bzl
+++ b/cpp/libclang/cpp_parser.bzl
@@ -274,6 +274,7 @@ def run_cpp_parser_action(
         output_prefix,
         tool,
         log_level,
+        root_anchor = "",
         extra_args = [],
         emit_debug_json = False):
     """Register the libclang parser action and return its declared outputs.
@@ -315,6 +316,12 @@ def run_cpp_parser_action(
             debug_json_output.path,
         ]
 
+    if root_anchor:
+        args += [
+            "--root-anchor",
+            root_anchor,
+        ]
+
     target_compilation_flags_list = target[CompilationFlagsInfo].flags.to_list()
 
     target_source_files_info = target[SourceFilesInfo]
diff --git a/cpp/libclang/src/main.rs b/cpp/libclang/src/main.rs
index d38f8b7b..e4321b56 100644
--- a/cpp/libclang/src/main.rs
+++ b/cpp/libclang/src/main.rs
@@ -48,6 +48,10 @@ struct Args {
     /// Debug JSON output path (internal use only)
     #[arg(long, hide = true)]
     debug_json_output: Option<PathBuf>,
+
+    /// Resolver root anchor for IDs emitted by this parser (internal use only)
+    #[arg(long, hide = true, default_value = "")]
+    root_anchor: String,
 }
 
 #[derive(Default)]
@@ -210,6 +214,37 @@ fn serialize_class_diagram(
     Ok(())
 }
 
+fn apply_root_anchor(
+    entities: &mut BTreeMap<String, SimpleEntity>,
+    free_functions: &mut [FreeFunctionDecl],
+    root_anchor: &str,
+) {
+    if root_anchor.is_empty() {
+        return;
+    }
+
+    let mut anchored_entities = BTreeMap::new();
+    for (_, mut entity) in std::mem::take(entities) {
+        entity.id = format!("{root_anchor}::{}", entity.id);
+        entity.enclosing_namespace_id = entity
+            .enclosing_namespace_id
+            .map(|namespace| format!("{root_anchor}::{namespace}"));
+        for relationship in &mut entity.relationships {
+            relationship.source = format!("{root_anchor}::{}", relationship.source);
+            relationship.target = format!("{root_anchor}::{}", relationship.target);
+        }
+        anchored_entities.insert(entity.id.clone(), entity);
+    }
+    *entities = anchored_entities;
+
+    for free_function in free_functions {
+        free_function.enclosing_namespace_id = Some(match &free_function.enclosing_namespace_id {
+            Some(namespace) if !namespace.is_empty() => format!("{root_anchor}::{namespace}"),
+            _ => root_anchor.to_string(),
+        });
+    }
+}
+
 fn ensure_output_parent_exists(path: &Path) -> Result<(), std::io::Error> {
     if let Some(parent) = path.parent() {
         fs::create_dir_all(parent)?;
@@ -251,6 +286,11 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         );
     }
 
+    apply_root_anchor(
+        &mut outputs.types,
+        &mut outputs.free_function_declarations,
+        &command_line_args.root_anchor,
+    );
     if let Some(debug_json_output) = &command_line_args.debug_json_output {
         write_debug_json(
             debug_json_output,
@@ -260,7 +300,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             &outputs.functions,
         )?;
     }
-
     serialize_class_diagram(
         &command_line_args.class_fbs_output,
         outputs.types,
diff --git a/plantuml/parser/integration_test/class_diagram/class_diagram_file_level_constructs/output.json b/plantuml/parser/integration_test/class_diagram/class_diagram_file_level_constructs/output.json
index b58281b6..3fb46826 100644
--- a/plantuml/parser/integration_test/class_diagram/class_diagram_file_level_constructs/output.json
+++ b/plantuml/parser/integration_test/class_diagram/class_diagram_file_level_constructs/output.json
@@ -70,7 +70,7 @@
         }
       },
       {
-        "id": "sample.file_level.<<template>>\\nTest<T>",
+        "id": "sample.file_level.TestTemplate",
         "name": "TestTemplate",
         "enclosing_namespace_id": "sample.file_level",
         "stereotypes": ["service"],
diff --git a/plantuml/parser/integration_test/class_diagram/class_diagram_syntax_coverage/output.json b/plantuml/parser/integration_test/class_diagram/class_diagram_syntax_coverage/output.json
index 80733141..d7e67c59 100644
--- a/plantuml/parser/integration_test/class_diagram/class_diagram_syntax_coverage/output.json
+++ b/plantuml/parser/integration_test/class_diagram/class_diagram_syntax_coverage/output.json
@@ -808,7 +808,7 @@
         }
       },
       {
-        "id": "sample.newline.<<template>>\\nTest<T>",
+        "id": "sample.newline.TestTemplate",
         "name": "TestTemplate",
         "enclosing_namespace_id": "sample.newline",
         "stereotypes": [
diff --git a/validation/core/integration_test/component_public_api/positive_public_api_match/expected.yaml b/plantuml/parser/integration_test/component_diagram/qualified_name_does_not_search_descendants/output.yaml
similarity index 81%
rename from validation/core/integration_test/component_public_api/positive_public_api_match/expected.yaml
rename to plantuml/parser/integration_test/component_diagram/qualified_name_does_not_search_descendants/output.yaml
index 898ecba3..3938afc2 100644
--- a/validation/core/integration_test/component_public_api/positive_public_api_match/expected.yaml
+++ b/plantuml/parser/integration_test/component_diagram/qualified_name_does_not_search_descendants/output.yaml
@@ -10,4 +10,8 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
-should_pass: true
+qualified_name_does_not_search_descendants.puml:
+  error:
+    type: "UnresolvedReference"
+    fields:
+      reference: "A.B"
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/class_diagram.puml b/plantuml/parser/integration_test/component_diagram/qualified_name_does_not_search_descendants/qualified_name_does_not_search_descendants.puml
similarity index 71%
rename from validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/class_diagram.puml
rename to plantuml/parser/integration_test/component_diagram/qualified_name_does_not_search_descendants/qualified_name_does_not_search_descendants.puml
index d4c5d3d7..16869484 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/class_diagram.puml
+++ b/plantuml/parser/integration_test/component_diagram/qualified_name_does_not_search_descendants/qualified_name_does_not_search_descendants.puml
@@ -10,19 +10,18 @@
 '
 ' SPDX-License-Identifier: Apache-2.0
 ' *******************************************************************************
+@startuml "Qualified Name Does Not Search Descendants"
 
-@startuml class_diagram
-
-namespace unit_1 {
-    class Controller {
-        + Execute() : void
+package "Root" as Root {
+    component "Group" as Group {
+        component "A" as A {
+            component "B" as B
+        }
     }
-}
 
-namespace unit_2 {
-    class Controller {
-        + Execute() : void
-    }
+    component "Target" as Target
+
+    A.B --> Target
 }
 
 @enduml
diff --git a/plantuml/parser/integration_test/component_diagram/relation_quoted_name/output.json b/plantuml/parser/integration_test/component_diagram/relation_quoted_name/output.json
index f4a34de9..9e336636 100644
--- a/plantuml/parser/integration_test/component_diagram/relation_quoted_name/output.json
+++ b/plantuml/parser/integration_test/component_diagram/relation_quoted_name/output.json
@@ -9,7 +9,7 @@
       "stereotype": null,
       "relations": [
         {
-          "target": "score::mw::log",
+          "target": "score.mw.log",
           "annotation": "verbose",
           "relation_type": "Dependency",
           "source_role": "None",
@@ -24,8 +24,8 @@
         "line": 14
       }
     },
-    "score::mw::log": {
-      "id": "score::mw::log",
+    "score.mw.log": {
+      "id": "score.mw.log",
       "name": "score::mw::log",
       "alias": null,
       "parent_id": null,
diff --git a/plantuml/parser/integration_test/sequence_diagram/combined_lifecycle_suffix/output.json b/plantuml/parser/integration_test/sequence_diagram/combined_lifecycle_suffix/output.json
index abaa33db..d040355b 100644
--- a/plantuml/parser/integration_test/sequence_diagram/combined_lifecycle_suffix/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/combined_lifecycle_suffix/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "alice"
       },
       {
         "display_name": "bob",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "bob"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/implicit_participant_from_message_endpoint/output.json b/plantuml/parser/integration_test/sequence_diagram/implicit_participant_from_message_endpoint/output.json
index ebec7051..c5b5d653 100644
--- a/plantuml/parser/integration_test/sequence_diagram/implicit_participant_from_message_endpoint/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/implicit_participant_from_message_endpoint/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Client"
       },
       {
         "display_name": "Service",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 18
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       }
     ],
     "root": {
@@ -39,4 +41,4 @@
       ]
     }
   }
-}
\ No newline at end of file
+}
diff --git a/plantuml/parser/integration_test/sequence_diagram/invalid_duplicate_participant_id/invalid_duplicate_participant_id.puml b/plantuml/parser/integration_test/sequence_diagram/invalid_duplicate_participant_id/invalid_duplicate_participant_id.puml
new file mode 100644
index 00000000..de0b56a4
--- /dev/null
+++ b/plantuml/parser/integration_test/sequence_diagram/invalid_duplicate_participant_id/invalid_duplicate_participant_id.puml
@@ -0,0 +1,19 @@
+' *******************************************************************************
+' Copyright (c) 2026 Contributors to the Eclipse Foundation
+'
+' See the NOTICE file(s) distributed with this work for additional
+' information regarding copyright ownership.
+'
+' This program and the accompanying materials are made available under the
+' terms of the Apache License Version 2.0 which is available at
+' https://www.apache.org/licenses/LICENSE-2.0
+'
+' SPDX-License-Identifier: Apache-2.0
+' *******************************************************************************
+
+@startuml invalid_duplicate_participant_id
+
+participant "svc:billing::InvoiceService" as inv1
+participant "billing::InvoiceService" as inv2
+
+@enduml
diff --git a/validation/core/integration_test/component_sequence/positive_exact_match/expected.yaml b/plantuml/parser/integration_test/sequence_diagram/invalid_duplicate_participant_id/output.yaml
similarity index 78%
rename from validation/core/integration_test/component_sequence/positive_exact_match/expected.yaml
rename to plantuml/parser/integration_test/sequence_diagram/invalid_duplicate_participant_id/output.yaml
index 898ecba3..072ddf68 100644
--- a/validation/core/integration_test/component_sequence/positive_exact_match/expected.yaml
+++ b/plantuml/parser/integration_test/sequence_diagram/invalid_duplicate_participant_id/output.yaml
@@ -10,4 +10,9 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
-should_pass: true
+invalid_duplicate_participant_id.puml:
+  error:
+    type: DuplicateParticipantId
+    fields:
+      participant_id: billing.InvoiceService
+      line: "17"
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/sequence_diagram.puml b/plantuml/parser/integration_test/sequence_diagram/invalid_free_text_participant_identifier/invalid_free_text_participant_identifier.puml
similarity index 78%
rename from validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/sequence_diagram.puml
rename to plantuml/parser/integration_test/sequence_diagram/invalid_free_text_participant_identifier/invalid_free_text_participant_identifier.puml
index e2dba124..0f492d2e 100644
--- a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/sequence_diagram.puml
+++ b/plantuml/parser/integration_test/sequence_diagram/invalid_free_text_participant_identifier/invalid_free_text_participant_identifier.puml
@@ -11,10 +11,11 @@
 ' SPDX-License-Identifier: Apache-2.0
 ' *******************************************************************************
 
-@startuml sequence_diagram
+@startuml invalid_free_text_participant_identifier
 
-participant "<u><size:14>unit_1::Controller</size></u>" as controller
+participant Caller
+participant "Display Service" as Service
 
-controller -> controller : Execute()
+Caller -> "Display Service": invalidReference
 
 @enduml
diff --git a/validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/expected.yaml b/plantuml/parser/integration_test/sequence_diagram/invalid_free_text_participant_identifier/output.yaml
similarity index 69%
rename from validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/expected.yaml
rename to plantuml/parser/integration_test/sequence_diagram/invalid_free_text_participant_identifier/output.yaml
index 898ecba3..dcf38070 100644
--- a/validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/expected.yaml
+++ b/plantuml/parser/integration_test/sequence_diagram/invalid_free_text_participant_identifier/output.yaml
@@ -10,4 +10,10 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
-should_pass: true
+invalid_free_text_participant_identifier.puml:
+  error:
+    type: InvalidParticipantIdentifier
+    fields:
+      participant: Display Service
+      reason: free-text participant display names require an alias for uid derivation
+      line: "19"
diff --git a/plantuml/parser/integration_test/sequence_diagram/lost_found_endpoint_resolution/output.json b/plantuml/parser/integration_test/sequence_diagram/lost_found_endpoint_resolution/output.json
index 6f8dcc0b..8ff30a32 100644
--- a/plantuml/parser/integration_test/sequence_diagram/lost_found_endpoint_resolution/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/lost_found_endpoint_resolution/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/participant_identifier_examples/output.json b/plantuml/parser/integration_test/sequence_diagram/participant_identifier_examples/output.json
index 75c0fc70..c0f4a333 100644
--- a/plantuml/parser/integration_test/sequence_diagram/participant_identifier_examples/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/participant_identifier_examples/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": "component"
+        "stereotype": "component",
+        "uid": "Service"
       },
       {
         "display_name": "Caller",
@@ -20,17 +21,19 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Caller"
       },
       {
-        "display_name": "Display Service",
-        "alias": null,
+        "display_name": "core::service::ResourceBuilder",
+        "alias": "Builder",
         "participant_type": "Participant",
         "source_location": {
           "file": "",
-          "line": 22
+          "line": 18
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "core.service.ResourceBuilder"
       }
     ],
     "root": {
@@ -42,22 +45,22 @@
             "message": "callByAlias()",
             "source_location": {
               "file": "",
-              "line": 19
+              "line": 20
             }
           }
         },
         {
           "Interaction": {
             "sender": "Service",
-            "receiver": "Display Service",
-            "message": "callByDisplayName()",
+            "receiver": "core.service.ResourceBuilder",
+            "message": "callByTypeTextAlias()",
             "source_location": {
               "file": "",
-              "line": 22
+              "line": 21
             }
           }
         }
       ]
     }
   }
-}
\ No newline at end of file
+}
diff --git a/plantuml/parser/integration_test/sequence_diagram/participant_identifier_examples/participant_identifier_examples.puml b/plantuml/parser/integration_test/sequence_diagram/participant_identifier_examples/participant_identifier_examples.puml
index db2971c2..59cacf8a 100644
--- a/plantuml/parser/integration_test/sequence_diagram/participant_identifier_examples/participant_identifier_examples.puml
+++ b/plantuml/parser/integration_test/sequence_diagram/participant_identifier_examples/participant_identifier_examples.puml
@@ -15,10 +15,9 @@
 
 participant "Display Service" as Service <<component>>
 participant Caller
+participant "core::service::ResourceBuilder" as Builder
 
 Caller -> Service : callByAlias()
-' Note: "Display Service" is a new participant that is implicitly created by
-'       the message endpoint resolution(confirmed by Plantuml Preview).
-Service -> "Display Service" : callByDisplayName()
+Service -> Builder : callByTypeTextAlias()
 
 @enduml
diff --git a/plantuml/parser/integration_test/sequence_diagram/recreate_destroyed_participant/output.json b/plantuml/parser/integration_test/sequence_diagram/recreate_destroyed_participant/output.json
index ac4bf207..2e55bf8b 100644
--- a/plantuml/parser/integration_test/sequence_diagram/recreate_destroyed_participant/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/recreate_destroyed_participant/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "A"
       },
       {
         "display_name": "B",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "B"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_arrow_direction/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_arrow_direction/output.json
index 507a60d1..a6f8308a 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_arrow_direction/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_arrow_direction/output.json
@@ -6,15 +6,23 @@
         "display_name": "A",
         "alias": null,
         "participant_type": "Participant",
-        "source_location": { "file": "", "line": 16 },
-        "stereotype": null
+        "source_location": {
+          "file": "",
+          "line": 16
+        },
+        "stereotype": null,
+        "uid": "A"
       },
       {
         "display_name": "B",
         "alias": null,
         "participant_type": "Participant",
-        "source_location": { "file": "", "line": 17 },
-        "stereotype": null
+        "source_location": {
+          "file": "",
+          "line": 17
+        },
+        "stereotype": null,
+        "uid": "B"
       }
     ],
     "root": {
@@ -24,7 +32,10 @@
             "sender": "A",
             "receiver": "B",
             "message": "solid right",
-            "source_location": { "file": "", "line": 19 }
+            "source_location": {
+              "file": "",
+              "line": 19
+            }
           }
         },
         {
@@ -32,7 +43,10 @@
             "sender": "B",
             "receiver": "A",
             "message": "solid left",
-            "source_location": { "file": "", "line": 20 }
+            "source_location": {
+              "file": "",
+              "line": 20
+            }
           }
         },
         {
@@ -40,7 +54,10 @@
             "sender": "A",
             "receiver": "B",
             "message": "dashed right",
-            "source_location": { "file": "", "line": 21 }
+            "source_location": {
+              "file": "",
+              "line": 21
+            }
           }
         },
         {
@@ -48,7 +65,10 @@
             "sender": "B",
             "receiver": "A",
             "message": "dashed left",
-            "source_location": { "file": "", "line": 22 }
+            "source_location": {
+              "file": "",
+              "line": 22
+            }
           }
         }
       ]
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_branch_node/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_branch_node/output.json
index 11afe05e..dc63b154 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_branch_node/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_branch_node/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Client"
       },
       {
         "display_name": "Service",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_early_exit_node/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_early_exit_node/output.json
index 6362c600..50799fee 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_early_exit_node/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_early_exit_node/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Client"
       },
       {
         "display_name": "Service",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_group_container/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_group_container/output.json
index 7e4df32c..573b738d 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_group_container/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_group_container/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Client"
       },
       {
         "display_name": "Service",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_interaction_node/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_interaction_node/output.json
index 5bf69da6..d858fb61 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_interaction_node/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_interaction_node/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Client"
       },
       {
         "display_name": "Service",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_lifecycle_nodes/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_lifecycle_nodes/output.json
index b9ab57d2..c1510fde 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_lifecycle_nodes/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_lifecycle_nodes/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Client"
       },
       {
         "display_name": "Service",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       },
       {
         "display_name": "Worker",
@@ -30,7 +32,8 @@
           "file": "",
           "line": 20
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Worker"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_loop_node/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_loop_node/output.json
index bc992062..1ba10aac 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_loop_node/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_loop_node/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Client"
       },
       {
         "display_name": "Service",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_message_direction/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_message_direction/output.json
index f88053a2..d3afb760 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_message_direction/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_message_direction/output.json
@@ -5,6 +5,7 @@
       {
         "display_name": "Service",
         "alias": null,
+        "uid": "Service",
         "participant_type": "Participant",
         "source_location": { "file": "", "line": 16 },
         "stereotype": null
@@ -12,6 +13,7 @@
       {
         "display_name": "Client1",
         "alias": null,
+        "uid": "Client1",
         "participant_type": "Participant",
         "source_location": { "file": "", "line": 17 },
         "stereotype": null
@@ -19,6 +21,7 @@
       {
         "display_name": "Client2",
         "alias": null,
+        "uid": "Client2",
         "participant_type": "Participant",
         "source_location": { "file": "", "line": 18 },
         "stereotype": null
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_parallel_node/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_parallel_node/output.json
index ba54bb2d..c888f292 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_parallel_node/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_parallel_node/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       },
       {
         "display_name": "Worker",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Worker"
       },
       {
         "display_name": "Audit",
@@ -30,7 +32,8 @@
           "file": "",
           "line": 18
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Audit"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/sequence_reference_node/output.json b/plantuml/parser/integration_test/sequence_diagram/sequence_reference_node/output.json
index 7c2ac1f7..66c50145 100644
--- a/plantuml/parser/integration_test/sequence_diagram/sequence_reference_node/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/sequence_reference_node/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Service"
       },
       {
         "display_name": "Worker",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": null
+        "stereotype": null,
+        "uid": "Worker"
       }
     ],
     "root": {
diff --git a/plantuml/parser/integration_test/sequence_diagram/simple_sequence/output.json b/plantuml/parser/integration_test/sequence_diagram/simple_sequence/output.json
index b836c2f1..cfbffc9e 100644
--- a/plantuml/parser/integration_test/sequence_diagram/simple_sequence/output.json
+++ b/plantuml/parser/integration_test/sequence_diagram/simple_sequence/output.json
@@ -10,7 +10,8 @@
           "file": "",
           "line": 16
         },
-        "stereotype": "component"
+        "stereotype": "component",
+        "uid": "ComponentA"
       },
       {
         "display_name": "Component B",
@@ -20,7 +21,8 @@
           "file": "",
           "line": 17
         },
-        "stereotype": "component"
+        "stereotype": "component",
+        "uid": "ComponentB"
       },
       {
         "display_name": "Component C",
@@ -30,7 +32,8 @@
           "file": "",
           "line": 18
         },
-        "stereotype": "component"
+        "stereotype": "component",
+        "uid": "ComponentC"
       }
     ],
     "root": {
@@ -141,17 +144,17 @@
                                               "line": 31
                                             }
                                           }
-                                          },
-                                          {
-                                            "Interaction": {
-                                              "sender": "ComponentC",
-                                              "receiver": "ComponentB",
-                                              "message": "Return Result",
-                                              "source_location": {
-                                                "file": "",
-                                                "line": 32
-                                              }
+                                        },
+                                        {
+                                          "Interaction": {
+                                            "sender": "ComponentC",
+                                            "receiver": "ComponentB",
+                                            "message": "Return Result",
+                                            "source_location": {
+                                              "file": "",
+                                              "line": 32
                                             }
+                                          }
                                         }
                                       ]
                                     },
@@ -215,17 +218,17 @@
                                               "line": 40
                                             }
                                           }
-                                          },
-                                          {
-                                            "Interaction": {
-                                              "sender": "ComponentC",
-                                              "receiver": "ComponentB",
-                                              "message": "Return Result",
-                                              "source_location": {
-                                                "file": "",
-                                                "line": 41
-                                              }
+                                        },
+                                        {
+                                          "Interaction": {
+                                            "sender": "ComponentC",
+                                            "receiver": "ComponentB",
+                                            "message": "Return Result",
+                                            "source_location": {
+                                              "file": "",
+                                              "line": 41
                                             }
+                                          }
                                         }
                                       ]
                                     },
@@ -248,17 +251,17 @@
                                               "line": 43
                                             }
                                           }
-                                          },
-                                          {
-                                            "Interaction": {
-                                              "sender": "ComponentC",
-                                              "receiver": "ComponentB",
-                                              "message": "Return Result",
-                                              "source_location": {
-                                                "file": "",
-                                                "line": 44
-                                              }
+                                        },
+                                        {
+                                          "Interaction": {
+                                            "sender": "ComponentC",
+                                            "receiver": "ComponentB",
+                                            "message": "Return Result",
+                                            "source_location": {
+                                              "file": "",
+                                              "line": 44
                                             }
+                                          }
                                         }
                                       ]
                                     },
diff --git a/plantuml/parser/integration_test/src/test_error_view.rs b/plantuml/parser/integration_test/src/test_error_view.rs
index d262ea9e..ed5bd3ab 100644
--- a/plantuml/parser/integration_test/src/test_error_view.rs
+++ b/plantuml/parser/integration_test/src/test_error_view.rs
@@ -346,6 +346,20 @@ impl ErrorView for SequenceResolverError {
     fn project(&self, base_dir: &Path) -> ProjectedError {
         let _ = base_dir;
         match self {
+            SequenceResolverError::InvalidParticipantIdentifier {
+                participant,
+                reason,
+                source_location,
+            } => ProjectedError::new("InvalidParticipantIdentifier")
+                .with_field("participant", participant.clone())
+                .with_field("reason", reason.clone())
+                .with_field("line", source_location.line.to_string()),
+            SequenceResolverError::DuplicateParticipantId {
+                participant_id,
+                source_location,
+            } => ProjectedError::new("DuplicateParticipantId")
+                .with_field("participant_id", participant_id.clone())
+                .with_field("line", source_location.line.to_string()),
             SequenceResolverError::DestroyedParticipantUse {
                 participant,
                 source_location,
diff --git a/plantuml/parser/puml_cli/src/main.rs b/plantuml/parser/puml_cli/src/main.rs
index 7575e09c..fd868b23 100644
--- a/plantuml/parser/puml_cli/src/main.rs
+++ b/plantuml/parser/puml_cli/src/main.rs
@@ -134,6 +134,12 @@ struct Args {
     /// be a single path component (no `/`, no `.`/`..`), never a path.
     #[arg(long)]
     output_stem: Option<String>,
+
+    /// Optional uid root anchor prefix for class/component/sequence resolvers.
+    /// This should come from the owning rules_score package context rather
+    /// than being derived from the input file path.
+    #[arg(long)]
+    root_anchor: Option<String>,
 }
 
 #[derive(Copy, Clone, ValueEnum, Debug)]
@@ -266,7 +272,7 @@ fn run() -> Result<(), Box<dyn std::error::Error>> {
             _ => None,
         };
 
-        match resolve_parsed_diagram(parsed_content) {
+        match resolve_parsed_diagram(parsed_content, args.root_anchor.as_deref()) {
             Ok(logic_result) => {
                 debug!(
                     "Successfully resolved PlantUML document: {}",
@@ -476,6 +482,7 @@ fn idmap_model_for(resolved: &ResolvedDiagram) -> Option<IdMapModel<'_>> {
 
 fn resolve_parsed_diagram(
     parsed_content: ParsedDiagram,
+    root_anchor: Option<&str>,
 ) -> Result<ResolvedDiagram, Box<dyn std::error::Error>> {
     match parsed_content {
         ParsedDiagram::Activity(parsed_content) => {
@@ -483,15 +490,15 @@ fn resolve_parsed_diagram(
             puml_resolver(&mut resolver, &parsed_content).map(ResolvedDiagram::Activity)
         }
         ParsedDiagram::Component(parsed_content) => {
-            let mut resolver = ComponentResolver::new();
+            let mut resolver = ComponentResolver::with_root_anchor(root_anchor);
             puml_resolver(&mut resolver, &parsed_content).map(ResolvedDiagram::Component)
         }
         ParsedDiagram::Class(parsed_content) => {
-            let mut resolver = ClassResolver::new();
+            let mut resolver = ClassResolver::with_root_anchor(root_anchor);
             puml_resolver(&mut resolver, &parsed_content).map(ResolvedDiagram::Class)
         }
         ParsedDiagram::Sequence(parsed_content) => {
-            let mut resolver = SequenceResolver;
+            let mut resolver = SequenceResolver::with_root_anchor(root_anchor);
             puml_resolver(&mut resolver, &parsed_content).map(ResolvedDiagram::Sequence)
         }
     }
@@ -875,7 +882,7 @@ B --> A : reply
         let parsed = parse_puml_file(&path, content, LogLevel::Info, DiagramType::Sequence)
             .expect("sequence parse must succeed");
 
-        let resolved = resolve_parsed_diagram(parsed);
+        let resolved = resolve_parsed_diagram(parsed, None);
         assert!(
             resolved.is_ok(),
             "sequence diagram must resolve without error; got: {:?}",
@@ -1071,7 +1078,7 @@ mod idmap_wiring_tests {
 
         let parsed = parse_puml_file(&path, content, LogLevel::Info, DiagramType::Activity)
             .expect("activity parse must succeed");
-        let resolved = resolve_parsed_diagram(parsed).expect("activity must resolve");
+        let resolved = resolve_parsed_diagram(parsed, None).expect("activity must resolve");
         assert!(
             matches!(resolved, ResolvedDiagram::Activity(_)),
             "activity diagram must resolve to the Activity variant that triggers the empty writer"
@@ -1127,7 +1134,7 @@ mod idmap_wiring_tests {
 
         let parsed = parse_puml_file(&path, content, LogLevel::Info, DiagramType::Component)
             .expect("component parse must succeed");
-        let resolved = resolve_parsed_diagram(parsed).expect("component must resolve");
+        let resolved = resolve_parsed_diagram(parsed, None).expect("component must resolve");
         assert!(matches!(resolved, ResolvedDiagram::Component(_)));
 
         let idmap_model =
@@ -1158,7 +1165,7 @@ mod idmap_wiring_tests {
 
         let parsed = parse_puml_file(&path, content, LogLevel::Info, DiagramType::Class)
             .expect("class parse must succeed");
-        let resolved = resolve_parsed_diagram(parsed).expect("class must resolve");
+        let resolved = resolve_parsed_diagram(parsed, None).expect("class must resolve");
         assert!(matches!(resolved, ResolvedDiagram::Class(_)));
 
         let idmap_model =
@@ -1194,7 +1201,7 @@ mod idmap_wiring_tests {
 
         let parsed = parse_puml_file(&source_path, content, LogLevel::Info, DiagramType::Class)
             .expect("class parse must succeed");
-        let resolved = resolve_parsed_diagram(parsed).expect("class diagram must resolve");
+        let resolved = resolve_parsed_diagram(parsed, None).expect("class diagram must resolve");
         let fbs_bytes = serialize_resolved_diagram(&resolved);
         let fbs_text = String::from_utf8_lossy(&fbs_bytes);
 
@@ -1230,7 +1237,7 @@ mod idmap_wiring_tests {
 
         let parsed = parse_puml_file(&path, content, LogLevel::Info, DiagramType::Class)
             .expect("class parse must succeed");
-        let resolved = resolve_parsed_diagram(parsed).expect("class must resolve");
+        let resolved = resolve_parsed_diagram(parsed, None).expect("class must resolve");
         let idmap_model =
             idmap_model_for(&resolved).expect("class diagrams must dispatch to an IdMapModel");
 
@@ -1289,7 +1296,7 @@ mod idmap_wiring_tests {
 
         let parsed = parse_puml_file(&path, content, LogLevel::Info, DiagramType::Sequence)
             .expect("sequence parse must succeed");
-        let resolved = resolve_parsed_diagram(parsed).expect("sequence must resolve");
+        let resolved = resolve_parsed_diagram(parsed, None).expect("sequence must resolve");
         assert!(matches!(resolved, ResolvedDiagram::Sequence(_)));
 
         let idmap_model =
@@ -1346,7 +1353,7 @@ mod idmap_wiring_tests {
         )
         .expect("component parse must succeed");
         let component_resolved =
-            resolve_parsed_diagram(component_parsed).expect("component must resolve");
+            resolve_parsed_diagram(component_parsed, None).expect("component must resolve");
         let component_idmap_model = idmap_model_for(&component_resolved)
             .expect("component diagrams must dispatch to an IdMapModel");
 
@@ -1365,7 +1372,8 @@ mod idmap_wiring_tests {
             DiagramType::Class,
         )
         .expect("class parse must succeed");
-        let class_resolved = resolve_parsed_diagram(class_parsed).expect("class must resolve");
+        let class_resolved =
+            resolve_parsed_diagram(class_parsed, None).expect("class must resolve");
         let class_idmap_model = idmap_model_for(&class_resolved)
             .expect("class diagrams must dispatch to an IdMapModel");
 
@@ -1420,4 +1428,58 @@ mod idmap_wiring_tests {
 
         cleanup_dir(&dir);
     }
+
+    #[test]
+    fn class_diagram_root_anchor_prefixes_defined_ids() {
+        let content = "@startuml\n\
+             package package_a {\n\
+                 interface \"InternalInterface\" as InternalInterface {\n\
+                     +GetData()\n\
+                 }\n\
+             }\n\
+             @enduml";
+        let path = Rc::new(PathBuf::from("cls/internal_api_diagram.puml"));
+
+        let parsed = parse_puml_file(&path, content, LogLevel::Info, DiagramType::Class)
+            .expect("class parse must succeed");
+        let resolved =
+            resolve_parsed_diagram(parsed, Some("score::logging")).expect("class must resolve");
+
+        let ResolvedDiagram::Class(model) = resolved else {
+            panic!("expected class diagram");
+        };
+
+        assert!(model
+            .entities
+            .iter()
+            .any(|entity| entity.id == "score.logging.package_a.InternalInterface"));
+    }
+
+    #[test]
+    fn sequence_diagram_root_anchor_prefixes_type_text_derived_participants() {
+        let content = "@startuml\nparticipant \"core::service::ResourceBuilder\" as Builder\nBuilder -> Builder : ping\n@enduml";
+        let path = Rc::new(PathBuf::from("seq/builder.puml"));
+
+        let parsed = parse_puml_file(&path, content, LogLevel::Info, DiagramType::Sequence)
+            .expect("sequence parse must succeed");
+        let resolved =
+            resolve_parsed_diagram(parsed, Some("score::logging")).expect("sequence must resolve");
+
+        let ResolvedDiagram::Sequence(model) = resolved else {
+            panic!("expected sequence diagram");
+        };
+
+        let sequence_logic::Node::Interaction(interaction) = &model.root.items[0] else {
+            panic!("expected interaction node");
+        };
+
+        assert_eq!(
+            interaction.sender.as_deref(),
+            Some("score.logging.core.service.ResourceBuilder")
+        );
+        assert_eq!(
+            interaction.receiver.as_deref(),
+            Some("score.logging.core.service.ResourceBuilder")
+        );
+    }
 }
diff --git a/plantuml/parser/puml_idmap/src/lib.rs b/plantuml/parser/puml_idmap/src/lib.rs
index 46b1c293..fdf4b6ea 100644
--- a/plantuml/parser/puml_idmap/src/lib.rs
+++ b/plantuml/parser/puml_idmap/src/lib.rs
@@ -504,6 +504,7 @@ mod tests {
         SequenceParticipant {
             display_name: name.to_string(),
             alias: None,
+            uid: name.to_string(),
             participant_type: ParticipantType::Participant,
             source_location: SourceLocation::new("test.puml", 0),
             stereotype: None,
diff --git a/plantuml/parser/puml_resolver/BUILD b/plantuml/parser/puml_resolver/BUILD
index 644b9821..7fc48831 100644
--- a/plantuml/parser/puml_resolver/BUILD
+++ b/plantuml/parser/puml_resolver/BUILD
@@ -10,7 +10,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
-load("@rules_rust//rust:defs.bzl", "rust_library")
+load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")
 
 rust_library(
     name = "puml_resolver",
@@ -22,6 +22,7 @@ rust_library(
         ":component_resolver",
         ":resolver_traits",
         ":sequence_resolver",
+        ":uid_normalization",
     ],
 )
 
@@ -61,3 +62,21 @@ rust_library(
         "@crates//:log",
     ],
 )
+
+rust_library(
+    name = "uid_normalization",
+    srcs = [
+        "src/uid_normalization.rs",
+    ],
+    crate_name = "uid_normalization",
+    crate_root = "src/uid_normalization.rs",
+    visibility = ["//plantuml/parser:__subpackages__"],
+    deps = [
+        "//tools/metamodel/common:uid_utils",
+    ],
+)
+
+rust_test(
+    name = "uid_normalization_unit_test",
+    crate = ":uid_normalization",
+)
diff --git a/plantuml/parser/puml_resolver/src/class_diagram/BUILD b/plantuml/parser/puml_resolver/src/class_diagram/BUILD
index 6c446a0a..12178924 100644
--- a/plantuml/parser/puml_resolver/src/class_diagram/BUILD
+++ b/plantuml/parser/puml_resolver/src/class_diagram/BUILD
@@ -25,6 +25,7 @@ rust_library(
         "//plantuml/parser/puml_parser:class_diagram",
         "//plantuml/parser/puml_parser:parser_core",
         "//plantuml/parser/puml_resolver:resolver_traits",
+        "//plantuml/parser/puml_resolver:uid_normalization",
         "//tools/metamodel/class:class_diagram",
         "@crates//:log",
         "@crates//:serde",
@@ -53,6 +54,7 @@ rust_test(
         "//plantuml/parser/puml_parser:class_diagram",
         "//plantuml/parser/puml_parser:parser_core",
         "//plantuml/parser/puml_resolver:resolver_traits",
+        "//plantuml/parser/puml_resolver:uid_normalization",
         "//plantuml/parser/puml_utils",
         "//tools/metamodel/class:class_diagram",
         "@crates//:serde",
diff --git a/plantuml/parser/puml_resolver/src/class_diagram/src/class_resolver.rs b/plantuml/parser/puml_resolver/src/class_diagram/src/class_resolver.rs
index ddc8bff8..6f6b453b 100644
--- a/plantuml/parser/puml_resolver/src/class_diagram/src/class_resolver.rs
+++ b/plantuml/parser/puml_resolver/src/class_diagram/src/class_resolver.rs
@@ -23,6 +23,10 @@ use class_parser::{
 use parser_core::common_ast::Arrow;
 use resolver_traits::DiagramResolver;
 use thiserror::Error;
+use uid_normalization::{
+    internal_scope_from_resolved_path, is_explicit_path, resolve_explicit_path, InternalScope,
+    RootAnchor,
+};
 
 #[derive(Debug, Error)]
 pub enum ClassPumlResolverError {
@@ -56,6 +60,7 @@ pub struct ClassResolver {
     pub logic: ClassDiagram,
     // internal name or alias -> FQN
     name_map: HashMap<String, String>,
+    root_anchor: RootAnchor,
 }
 
 impl Default for ClassResolver {
@@ -66,6 +71,10 @@ impl Default for ClassResolver {
 
 impl ClassResolver {
     pub fn new() -> Self {
+        Self::with_root_anchor(None)
+    }
+
+    pub fn with_root_anchor(root_anchor: Option<&str>) -> Self {
         Self {
             logic: ClassDiagram {
                 name: String::new(),
@@ -73,6 +82,7 @@ impl ClassResolver {
                 free_functions: Vec::new(),
             },
             name_map: HashMap::new(),
+            root_anchor: RootAnchor::new(root_anchor),
         }
     }
 
@@ -105,27 +115,17 @@ impl ClassResolver {
         }
     }
 
-    fn normalize_fqn(raw: &str) -> String {
-        raw.replace("::", ".").trim_matches('.').to_string()
+    fn resolve_class_id(&self, name: &str, parent: &Option<String>) -> String {
+        self.resolve_parent_scope(parent)
+            .resolve_with_leaf(&self.root_anchor, name)
     }
 
-    fn build_fqn(&self, name: &str, parent: &Option<String>) -> String {
-        let normalized_name = Self::normalize_fqn(name);
-
-        match parent {
-            Some(p) => {
-                let normalized_parent = Self::normalize_fqn(p);
+    fn id_leaf(name: &Name) -> &str {
+        name.display.as_deref().unwrap_or(&name.internal)
+    }
 
-                if normalized_parent.is_empty() {
-                    normalized_name
-                } else if normalized_name.is_empty() {
-                    normalized_parent
-                } else {
-                    format!("{}.{}", normalized_parent, normalized_name)
-                }
-            }
-            None => normalized_name,
-        }
+    fn resolve_parent_scope(&self, parent: &Option<String>) -> InternalScope {
+        internal_scope_from_resolved_path(&self.root_anchor, parent.as_deref())
     }
 
     fn entity_name(name: &Name) -> String {
@@ -144,13 +144,15 @@ impl ClassResolver {
 
     fn resolve_name(&self, name: &str, parent: &Option<String>) -> Option<String> {
         // 1. FQN
-        if name.contains('.') || name.contains("::") {
-            return Some(Self::normalize_fqn(name));
+        if is_explicit_path(name) {
+            return Some(resolve_explicit_path(&self.root_anchor, name));
         }
 
         // 2. Current Namespace
         if let Some(p) = parent {
-            let candidate = format!("{}.{}", p, name);
+            let candidate = self
+                .resolve_parent_scope(&Some(p.clone()))
+                .resolve_with_leaf(&self.root_anchor, name);
 
             if self.logic.entities.iter().any(|e| e.id == candidate) {
                 return Some(candidate);
@@ -177,11 +179,11 @@ impl ClassResolver {
     ) -> Result<(), ClassPumlResolverError> {
         match elem {
             ClassUmlTopLevel::Types(element) => {
-                self.process_element(element, parent);
+                self.process_element(element, parent)?;
             }
 
             ClassUmlTopLevel::Enum(enum_def) => {
-                self.process_enum(enum_def, parent);
+                self.process_enum(enum_def, parent)?;
             }
 
             ClassUmlTopLevel::Namespace(ns) => {
@@ -221,10 +223,10 @@ impl ClassResolver {
         pkg: &Package,
         parent: Option<String>,
     ) -> Result<(), ClassPumlResolverError> {
-        let fqn = self.build_fqn(&pkg.name.internal, &parent);
+        let fqn = self.resolve_class_id(Self::id_leaf(&pkg.name), &parent);
 
         for t in &pkg.types {
-            self.process_element(t, Some(fqn.clone()));
+            self.process_element(t, Some(fqn.clone()))?;
         }
 
         for sub in &pkg.packages {
@@ -243,10 +245,10 @@ impl ClassResolver {
         ns: &Namespace,
         parent: Option<String>,
     ) -> Result<(), ClassPumlResolverError> {
-        let fqn = self.build_fqn(&ns.name.internal, &parent);
+        let fqn = self.resolve_class_id(Self::id_leaf(&ns.name), &parent);
 
         for t in &ns.types {
-            self.process_element(t, Some(fqn.clone()));
+            self.process_element(t, Some(fqn.clone()))?;
         }
 
         for sub in &ns.namespaces {
@@ -261,7 +263,7 @@ impl ClassResolver {
         pkg: &Package,
         parent: Option<String>,
     ) -> Result<(), ClassPumlResolverError> {
-        let fqn = self.build_fqn(&pkg.name.internal, &parent);
+        let fqn = self.resolve_class_id(Self::id_leaf(&pkg.name), &parent);
 
         for t in &pkg.types {
             self.process_declared_relations_element(t, Some(fqn.clone()))?;
@@ -279,7 +281,7 @@ impl ClassResolver {
         ns: &Namespace,
         parent: Option<String>,
     ) -> Result<(), ClassPumlResolverError> {
-        let fqn = self.build_fqn(&ns.name.internal, &parent);
+        let fqn = self.resolve_class_id(Self::id_leaf(&ns.name), &parent);
 
         for t in &ns.types {
             self.process_declared_relations_element(t, Some(fqn.clone()))?;
@@ -300,13 +302,13 @@ impl ClassResolver {
         match element {
             Element::ClassDef(def) => {
                 self.process_extends_relationships(
-                    &def.name.internal,
+                    Self::id_leaf(&def.name),
                     &def.extends,
                     parent.clone(),
                     &def.source_location,
                 )?;
                 self.process_implements_relationships(
-                    &def.name.internal,
+                    Self::id_leaf(&def.name),
                     &def.implements,
                     parent,
                     &def.source_location,
@@ -314,7 +316,7 @@ impl ClassResolver {
             }
             Element::InterfaceDef(def) => {
                 self.process_extends_relationships(
-                    &def.name.internal,
+                    Self::id_leaf(&def.name),
                     &def.extends,
                     parent,
                     &def.source_location,
@@ -370,7 +372,7 @@ impl ClassResolver {
             return Ok(());
         }
 
-        let source = self.build_fqn(source_name, &parent);
+        let source = self.resolve_class_id(source_name, &parent);
 
         for declared_target in targets {
             let target = self.resolve_name(declared_target, &parent).ok_or_else(|| {
@@ -392,9 +394,13 @@ impl ClassResolver {
         Ok(())
     }
 
-    fn process_element(&mut self, element: &Element, parent: Option<String>) {
+    fn process_element(
+        &mut self,
+        element: &Element,
+        parent: Option<String>,
+    ) -> Result<(), ClassPumlResolverError> {
         match element {
-            Element::EnumDef(def) => self.process_enum(def, parent),
+            Element::EnumDef(def) => self.process_enum(def, parent)?,
             _ => {
                 let entity_type = match element {
                     Element::ClassDef(def) if def.is_abstract => EntityType::AbstractClass,
@@ -403,12 +409,19 @@ impl ClassResolver {
                     Element::InterfaceDef(_) => EntityType::Interface,
                     _ => unreachable!(),
                 };
-                self.process_class(element, parent, entity_type);
+                self.process_class(element, parent, entity_type)?;
             }
         }
+
+        Ok(())
     }
 
-    fn process_class(&mut self, def: &Element, parent: Option<String>, entity_type: EntityType) {
+    fn process_class(
+        &mut self,
+        def: &Element,
+        parent: Option<String>,
+        entity_type: EntityType,
+    ) -> Result<(), ClassPumlResolverError> {
         let (
             name,
             stereotypes,
@@ -450,7 +463,7 @@ impl ClassResolver {
             }
         };
 
-        let id = self.build_fqn(&name.internal, &parent);
+        let id = self.resolve_class_id(Self::id_leaf(name), &parent);
 
         let template_parameters =
             Self::convert_class_template_parameters(template_parameters, methods);
@@ -473,8 +486,29 @@ impl ClassResolver {
             source_location: source_location.clone(),
         };
 
-        self.register_entity_names(name, &id);
+        self.push_entity(entity, name)?;
+        Ok(())
+    }
+
+    fn push_entity(
+        &mut self,
+        entity: SimpleEntity,
+        name: &Name,
+    ) -> Result<(), ClassPumlResolverError> {
+        if self
+            .logic
+            .entities
+            .iter()
+            .any(|existing| existing.id == entity.id)
+        {
+            return Err(ClassPumlResolverError::DuplicateEntity {
+                entity_id: entity.id.clone(),
+            });
+        }
+
+        self.register_entity_names(name, &entity.id);
         self.logic.entities.push(entity);
+        Ok(())
     }
 
     fn convert_type_alias(type_alias: &ParserTypeAlias) -> TypeAlias {
@@ -642,8 +676,12 @@ impl ClassResolver {
         }
     }
 
-    fn process_enum(&mut self, def: &EnumDef, parent: Option<String>) {
-        let id = self.build_fqn(&def.name.internal, &parent);
+    fn process_enum(
+        &mut self,
+        def: &EnumDef,
+        parent: Option<String>,
+    ) -> Result<(), ClassPumlResolverError> {
+        let id = self.resolve_class_id(Self::id_leaf(&def.name), &parent);
 
         let mut last_value: Option<i128> = None;
         let literals = def
@@ -671,7 +709,7 @@ impl ClassResolver {
             })
             .collect();
 
-        self.logic.entities.push(SimpleEntity {
+        let entity = SimpleEntity {
             id: id.clone(),
             name: Self::entity_name(&def.name),
             enclosing_namespace_id: parent.clone(),
@@ -684,9 +722,10 @@ impl ClassResolver {
             enum_literals: literals,
             relationships: vec![],
             source_location: def.source_location.clone(),
-        });
+        };
 
-        self.register_entity_names(&def.name, &id);
+        self.push_entity(entity, &def.name)?;
+        Ok(())
     }
 
     fn convert_arrow(&self, arrow: &Arrow) -> Result<(RelationType, bool), ClassPumlResolverError> {
@@ -871,6 +910,13 @@ mod tests {
         }
     }
 
+    fn make_name_with_alias(internal: &str, alias: &str) -> Name {
+        Name {
+            internal: internal.to_string(),
+            display: Some(alias.to_string()),
+        }
+    }
+
     fn make_class(name: &str) -> Element {
         Element::ClassDef(ClassDef {
             name: make_name(name),
@@ -918,40 +964,58 @@ mod tests {
     }
 
     // ----------------------------
-    // build_fqn
+    // resolve_class_id
     // ----------------------------
     #[test]
-    fn test_build_fqn_root() {
+    fn test_resolve_class_id_root() {
         let resolver = ClassResolver::new();
-        let fqn = resolver.build_fqn("User", &None);
+        let fqn = resolver.resolve_class_id("User", &None);
         assert_eq!(fqn, "User");
     }
 
     #[test]
-    fn test_build_fqn_nested() {
+    fn test_resolve_class_id_nested() {
         let resolver = ClassResolver::new();
-        let fqn = resolver.build_fqn("User", &Some("core".to_string()));
+        let fqn = resolver.resolve_class_id("User", &Some("core".to_string()));
         assert_eq!(fqn, "core.User");
     }
 
     #[test]
-    fn test_build_fqn_normalizes_namespace_separator() {
+    fn test_resolve_class_id_normalizes_namespace_separator() {
         let resolver = ClassResolver::new();
 
-        let root_fqn = resolver.build_fqn("core::geometry", &None);
-        let nested_fqn = resolver.build_fqn("User", &Some("core::geometry".to_string()));
+        let root_fqn = resolver.resolve_class_id("core::geometry", &None);
+        let nested_fqn = resolver.resolve_class_id("User", &Some("core::geometry".to_string()));
 
         assert_eq!(root_fqn, "core.geometry");
         assert_eq!(nested_fqn, "core.geometry.User");
     }
 
+    #[test]
+    fn test_resolve_class_id_prefixes_root_anchor() {
+        let resolver = ClassResolver::with_root_anchor(Some("score::logging"));
+
+        let fqn = resolver.resolve_class_id("User", &Some("core".to_string()));
+
+        assert_eq!(fqn, "score.logging.core.User");
+    }
+
+    #[test]
+    fn test_resolve_class_id_does_not_double_prefix_rooted_parent() {
+        let resolver = ClassResolver::with_root_anchor(Some("score::logging"));
+
+        let fqn = resolver.resolve_class_id("User", &Some("score.logging.core".to_string()));
+
+        assert_eq!(fqn, "score.logging.core.User");
+    }
+
     // ----------------------------
     // process_class
     // ----------------------------
     #[test]
     fn test_process_class() {
         let mut resolver = ClassResolver::new();
-        resolver.process_element(&make_class("User"), None);
+        resolver.process_element(&make_class("User"), None).unwrap();
         assert_eq!(resolver.logic.entities.len(), 1);
 
         let entity = &resolver.logic.entities[0];
@@ -960,13 +1024,31 @@ mod tests {
         assert_eq!(entity.entity_type, EntityType::Class);
     }
 
+    #[test]
+    fn test_process_class_prefers_alias_for_id_leaf() {
+        let mut resolver = ClassResolver::new();
+        let mut element = make_class("Sample Library API");
+
+        let Element::ClassDef(class_def) = &mut element else {
+            unreachable!("expected class element")
+        };
+        class_def.name = make_name_with_alias("Sample Library API", "SampleLibraryAPI");
+
+        resolver.process_element(&element, None).unwrap();
+
+        let entity = &resolver.logic.entities[0];
+        assert_eq!(entity.id, "SampleLibraryAPI");
+    }
+
     // ----------------------------
     // process_enum
     // ----------------------------
     #[test]
     fn test_process_enum() {
         let mut resolver = ClassResolver::new();
-        resolver.process_element(&make_enum("Color", vec!["Red", "Green", "Blue"]), None);
+        resolver
+            .process_element(&make_enum("Color", vec!["Red", "Green", "Blue"]), None)
+            .unwrap();
 
         assert_eq!(resolver.logic.entities.len(), 1);
 
@@ -976,13 +1058,29 @@ mod tests {
         assert_eq!(entity.enum_literals.len(), 3);
     }
 
+    #[test]
+    fn test_process_enum_prefers_alias_for_id_leaf() {
+        let mut resolver = ClassResolver::new();
+        let mut element = make_enum("Event Level", vec!["Info"]);
+
+        let Element::EnumDef(enum_def) = &mut element else {
+            unreachable!("expected enum element")
+        };
+        enum_def.name = make_name_with_alias("Event Level", "EventLevel");
+
+        resolver.process_element(&element, None).unwrap();
+
+        let entity = &resolver.logic.entities[0];
+        assert_eq!(entity.id, "EventLevel");
+    }
+
     // ----------------------------
     // resolve_name
     // ----------------------------
     #[test]
     fn test_resolve_name_global() {
         let mut resolver = ClassResolver::new();
-        resolver.process_element(&make_class("User"), None);
+        resolver.process_element(&make_class("User"), None).unwrap();
 
         let resolved = resolver.resolve_name("User", &None);
         assert_eq!(resolved, Some("User".to_string()));
@@ -991,7 +1089,9 @@ mod tests {
     #[test]
     fn test_resolve_name_namespace() {
         let mut resolver = ClassResolver::new();
-        resolver.process_element(&make_class("User"), Some("core".to_string()));
+        resolver
+            .process_element(&make_class("User"), Some("core".to_string()))
+            .unwrap();
 
         let resolved = resolver.resolve_name("User", &Some("core".to_string()));
         assert_eq!(resolved, Some("core.User".to_string()));
@@ -1006,6 +1106,18 @@ mod tests {
         assert_eq!(resolved, Some("core.geometry.User".to_string()));
     }
 
+    #[test]
+    fn test_resolve_name_treats_explicit_scope_path_as_relative_to_root_anchor() {
+        let resolver = ClassResolver::with_root_anchor(Some("score::logging"));
+
+        let resolved = resolver.resolve_name("core::geometry::User", &None);
+
+        assert_eq!(
+            resolved,
+            Some("score.logging.core.geometry.User".to_string())
+        );
+    }
+
     // ----------------------------
     // convert_arrow
     // ----------------------------
@@ -1101,8 +1213,8 @@ mod tests {
     fn test_process_relationship_inheritance() {
         let mut resolver = ClassResolver::new();
 
-        resolver.process_element(&make_class("A"), None);
-        resolver.process_element(&make_class("B"), None);
+        resolver.process_element(&make_class("A"), None).unwrap();
+        resolver.process_element(&make_class("B"), None).unwrap();
 
         let rel = ParserRelationship {
             left: "A".to_string(),
@@ -1174,6 +1286,24 @@ mod tests {
         assert_eq!(entity.id, "core.geometry.User");
     }
 
+    #[test]
+    fn test_duplicate_class_ids_are_rejected() {
+        let mut resolver = ClassResolver::new();
+
+        resolver
+            .process_element(&make_class("core::User"), None)
+            .unwrap();
+        let err = resolver
+            .process_element(&make_class("core.User"), None)
+            .expect_err("duplicate normalized class ids must fail");
+
+        assert!(matches!(
+            err,
+            ClassPumlResolverError::DuplicateEntity { ref entity_id }
+                if entity_id == "core.User"
+        ));
+    }
+
     // ----------------------------
     // resolve integration
     // ----------------------------
diff --git a/plantuml/parser/puml_resolver/src/component_diagram/BUILD b/plantuml/parser/puml_resolver/src/component_diagram/BUILD
index 8514b542..9935dd17 100644
--- a/plantuml/parser/puml_resolver/src/component_diagram/BUILD
+++ b/plantuml/parser/puml_resolver/src/component_diagram/BUILD
@@ -24,6 +24,8 @@ rust_library(
     deps = [
         "//plantuml/parser/puml_parser:component_diagram",
         "//plantuml/parser/puml_resolver:resolver_traits",
+        "//plantuml/parser/puml_resolver:uid_normalization",
+        "//tools/metamodel/common:uid_utils",
         "//tools/metamodel/component:component_diagram",
         "@crates//:log",
         "@crates//:thiserror",
@@ -47,7 +49,9 @@ rust_test(
         "//plantuml/parser/puml_parser:component_diagram",
         "//plantuml/parser/puml_parser:parser_core",
         "//plantuml/parser/puml_resolver:resolver_traits",
+        "//plantuml/parser/puml_resolver:uid_normalization",
         "//plantuml/parser/puml_utils",
+        "//tools/metamodel/common:uid_utils",
         "//tools/metamodel/component:component_diagram",
         "@crates//:serde_json",
     ],
diff --git a/plantuml/parser/puml_resolver/src/component_diagram/src/component_resolver.rs b/plantuml/parser/puml_resolver/src/component_diagram/src/component_resolver.rs
index 24a4233e..bfbcfdb5 100644
--- a/plantuml/parser/puml_resolver/src/component_diagram/src/component_resolver.rs
+++ b/plantuml/parser/puml_resolver/src/component_diagram/src/component_resolver.rs
@@ -19,6 +19,8 @@ use component_diagram::{
 };
 use component_parser::{Arrow, CompPumlDocument, Element, Port, PortType, Relation, Statement};
 use resolver_traits::DiagramResolver;
+use uid_normalization::{is_explicit_path, resolve_explicit_path, InternalScope, RootAnchor};
+use uid_utils::{normalize, normalized_segments};
 
 #[derive(Debug, thiserror::Error)]
 pub enum ComponentResolverError {
@@ -83,10 +85,15 @@ pub struct ComponentResolver {
     /// Maps port FQN -> parser port type (`port` / `portin` / `portout`)
     pub port_types: HashMap<String, PortType>,
     pending_relations: Vec<PendingRelation>,
+    root_anchor: RootAnchor,
 }
 
 impl ComponentResolver {
     pub fn new() -> Self {
+        Self::with_root_anchor(None)
+    }
+
+    pub fn with_root_anchor(root_anchor: Option<&str>) -> Self {
         Self {
             scope: Vec::new(),
             elements: HashMap::new(),
@@ -94,6 +101,24 @@ impl ComponentResolver {
             port_parents: HashMap::new(),
             port_types: HashMap::new(),
             pending_relations: Vec::new(),
+            root_anchor: RootAnchor::new(root_anchor),
+        }
+    }
+
+    fn resolve_parent_scope(&self, scope: &[String]) -> String {
+        InternalScope::new(scope.iter().map(String::as_str)).resolve(&self.root_anchor)
+    }
+
+    fn resolve_component_id(&self, scope: &[String], parts: &[&str]) -> String {
+        let mut internal_scope = scope.iter().map(String::as_str).collect::<Vec<_>>();
+        let leaf = parts.split_last();
+
+        match leaf {
+            Some((leaf, prefix)) => {
+                internal_scope.extend(prefix.iter().copied());
+                InternalScope::new(internal_scope).resolve_with_leaf(&self.root_anchor, leaf)
+            }
+            None => InternalScope::new(internal_scope).resolve(&self.root_anchor),
         }
     }
 
@@ -124,7 +149,7 @@ impl ComponentResolver {
         let mut candidate = scope.to_vec();
         candidate.push(port_local.to_string());
 
-        let direct_fqn = candidate.join(".");
+        let direct_fqn = self.resolve_component_id(scope, &[port_local]);
         if self.port_parents.contains_key(&direct_fqn) {
             return vec![direct_fqn];
         }
@@ -132,7 +157,7 @@ impl ComponentResolver {
         // 2. scope prefix
         // Search at any depth below the current scope: a port whose simple alias matches
         // and whose parent element is a descendant of (or equal to) the current scope.
-        let scope_prefix = scope.join(".");
+        let scope_prefix = self.resolve_parent_scope(scope);
         for (pfqn, parent_comp) in &self.port_parents {
             let pfqn_last = match pfqn.rfind('.') {
                 Some(i) => &pfqn[i + 1..],
@@ -179,11 +204,7 @@ impl ComponentResolver {
         found: &mut BTreeSet<String>,
     ) {
         // 1. direct FQN check
-        let fqn = if scope.is_empty() {
-            parts.join(".")
-        } else {
-            format!("{}.{}", scope.join("."), parts.join("."))
-        };
+        let fqn = self.resolve_component_id(scope, parts);
 
         if self.elements.contains_key(&fqn) {
             found.insert(fqn);
@@ -193,7 +214,7 @@ impl ComponentResolver {
         let scope_key = if scope.is_empty() {
             None
         } else {
-            Some(scope.join("."))
+            Some(self.resolve_parent_scope(scope))
         };
 
         let children: &[String] = self
@@ -221,15 +242,17 @@ impl ComponentResolver {
     /// Collect possible port FQN candidates from a raw reference token.
     /// Returns deduplicated, deterministic candidates (sorted by `BTreeSet`).
     fn collect_port_fqn_candidates_for_raw(&self, raw: &str) -> Vec<String> {
-        let parts: Vec<&str> = raw.split('.').collect();
+        let normalized_raw = normalize(raw);
+        let parts = normalized_segments(raw);
+        let part_refs = parts.iter().map(String::as_str).collect::<Vec<_>>();
         let mut candidates = std::collections::BTreeSet::new();
 
         // 1. scope-based lookup (only for simple name)
-        if parts.len() == 1 {
+        if part_refs.len() == 1 {
             for i in (0..=self.scope.len()).rev() {
                 let outer_scope = &self.scope[..i];
                 let matches =
-                    self.collect_matching_port_fqns_in_scope_or_children(outer_scope, raw);
+                    self.collect_matching_port_fqns_in_scope_or_children(outer_scope, part_refs[0]);
                 if !matches.is_empty() {
                     // Keep nearest-scope matches only for simple names.
                     candidates.extend(matches);
@@ -239,17 +262,14 @@ impl ComponentResolver {
         }
 
         // 2. relative FQN (scope + parts)
-        let mut relative = self.scope.clone();
-        relative.extend(parts.iter().map(|p| p.to_string()));
-
-        let relative_port_fqn = relative.join(".");
+        let relative_port_fqn = self.resolve_component_id(&self.scope, &part_refs);
         if self.port_types.contains_key(&relative_port_fqn) {
             candidates.insert(relative_port_fqn);
         }
 
         // 3. direct match
-        if self.port_types.contains_key(raw) {
-            candidates.insert(raw.to_string());
+        if self.port_types.contains_key(&normalized_raw) {
+            candidates.insert(normalized_raw);
         }
 
         candidates.into_iter().collect()
@@ -307,11 +327,7 @@ impl ComponentResolver {
     }
 
     fn make_fqn(&self, local: &str) -> String {
-        if self.scope.is_empty() {
-            local.to_string()
-        } else {
-            format!("{}.{}", self.scope.join("."), local)
-        }
+        self.resolve_component_id(&self.scope, &[local])
     }
 
     /// Resolve relation references, supporting:
@@ -323,20 +339,22 @@ impl ComponentResolver {
     /// - If any stage returns multiple valid candidates, return
     ///   `ComponentResolverError::AmbiguousReference` immediately.
     pub fn resolve_ref(&self, raw: &str) -> Result<String, ComponentResolverError> {
-        let parts: Vec<&str> = raw.split('.').collect();
+        let normalized_raw = normalize(raw);
+        let parts = normalized_segments(raw);
+        let part_refs = parts.iter().map(String::as_str).collect::<Vec<_>>();
 
         // 1. simple name
-        if parts.len() == 1 {
-            if let Some(res) = self.resolve_simple_name(parts[0], raw)? {
+        if part_refs.len() == 1 {
+            if let Some(res) = self.resolve_simple_name(part_refs[0], raw)? {
                 return Ok(res);
             }
         }
 
         // 2. relative qualified name
-        if let Some(res) = self.resolve_relative(&parts)? {
+        if let Some(res) = self.resolve_relative(&part_refs)? {
             // A distinct top-level element can also match the literal text;
             // silently preferring the scope-relative hit would shadow it.
-            let absolute_fqn = parts.join(".");
+            let absolute_fqn = resolve_explicit_path(&self.root_anchor, &normalized_raw);
             if absolute_fqn != res && self.elements.contains_key(&absolute_fqn) {
                 let mut candidates = vec![res, absolute_fqn];
                 candidates.sort();
@@ -349,9 +367,11 @@ impl ComponentResolver {
         }
 
         // 3. absolute FQN
-        let fqn = parts.join(".");
-        if self.elements.contains_key(&fqn) {
-            return Ok(fqn);
+        if is_explicit_path(raw) {
+            let fqn = resolve_explicit_path(&self.root_anchor, &normalized_raw);
+            if self.elements.contains_key(&fqn) {
+                return Ok(fqn);
+            }
         }
 
         error!("Unresolved reference: {}", raw);
@@ -408,9 +428,13 @@ impl ComponentResolver {
     }
 
     fn resolve_relative(&self, parts: &[&str]) -> Result<Option<String>, ComponentResolverError> {
-        let matches = self.collect_element_fqns_in_scope_or_children(&self.scope, parts);
+        let fqn = self.resolve_component_id(&self.scope, parts);
 
-        Self::pick_unique(matches, &parts.join("."))
+        if self.elements.contains_key(&fqn) {
+            Ok(Some(fqn))
+        } else {
+            Ok(None)
+        }
     }
 
     fn walk_scopes_nearest_first<F>(
@@ -786,7 +810,8 @@ impl ComponentResolver {
         } else {
             // Nested port: record port_fqn -> parent_fqn for relation lifting.
             self.port_types.insert(fqn.clone(), port.port_type);
-            self.port_parents.insert(fqn, self.scope.join("."));
+            self.port_parents
+                .insert(fqn, self.resolve_parent_scope(&self.scope));
         }
     }
 
@@ -806,7 +831,7 @@ impl ComponentResolver {
         let parent_id = if self.scope.is_empty() {
             None
         } else {
-            Some(self.scope.join("."))
+            Some(self.resolve_parent_scope(&self.scope))
         };
 
         let logic = LogicComponent {
diff --git a/plantuml/parser/puml_resolver/src/component_diagram/tests/component_resolver_test.rs b/plantuml/parser/puml_resolver/src/component_diagram/tests/component_resolver_test.rs
index 58424c9f..57ac3ded 100644
--- a/plantuml/parser/puml_resolver/src/component_diagram/tests/component_resolver_test.rs
+++ b/plantuml/parser/puml_resolver/src/component_diagram/tests/component_resolver_test.rs
@@ -89,6 +89,11 @@ fn test_relation_relative_name() {
     run_component_resolver_case("relation_relative_name");
 }
 
+#[test]
+fn test_qualified_name_does_not_search_descendants() {
+    run_component_resolver_case("qualified_name_does_not_search_descendants");
+}
+
 #[test]
 fn test_relation_simple_name_alias() {
     run_component_resolver_case("relation_simple_name_alias");
diff --git a/plantuml/parser/puml_resolver/src/sequence_diagram/BUILD b/plantuml/parser/puml_resolver/src/sequence_diagram/BUILD
index c488d0ea..09285394 100644
--- a/plantuml/parser/puml_resolver/src/sequence_diagram/BUILD
+++ b/plantuml/parser/puml_resolver/src/sequence_diagram/BUILD
@@ -30,6 +30,8 @@ rust_library(
         "//plantuml/parser/puml_parser:parser_core",
         "//plantuml/parser/puml_parser:sequence_diagram",
         "//plantuml/parser/puml_resolver:resolver_traits",
+        "//plantuml/parser/puml_resolver:uid_normalization",
+        "//tools/metamodel/common:uid_utils",
         "//tools/metamodel/sequence:sequence_diagram",
         "@crates//:log",
         "@crates//:serde",
@@ -57,7 +59,9 @@ rust_test(
         "//plantuml/parser/puml_parser:parser_core",
         "//plantuml/parser/puml_parser:sequence_diagram",
         "//plantuml/parser/puml_resolver:resolver_traits",
+        "//plantuml/parser/puml_resolver:uid_normalization",
         "//plantuml/parser/puml_utils",
+        "//tools/metamodel/common:uid_utils",
         "//tools/metamodel/sequence:sequence_diagram",
         "@crates//:serde",
         "@crates//:serde_json",
diff --git a/plantuml/parser/puml_resolver/src/sequence_diagram/src/error.rs b/plantuml/parser/puml_resolver/src/sequence_diagram/src/error.rs
index 340f9048..28499690 100644
--- a/plantuml/parser/puml_resolver/src/sequence_diagram/src/error.rs
+++ b/plantuml/parser/puml_resolver/src/sequence_diagram/src/error.rs
@@ -15,6 +15,21 @@ use sequence_logic::SourceLocation;
 
 #[derive(Debug, Clone, PartialEq, Eq, thiserror::Error)]
 pub enum SequenceResolverError {
+    #[error(
+        "invalid sequence participant identifier `{participant}` at {source_location}: {reason}"
+    )]
+    InvalidParticipantIdentifier {
+        participant: String,
+        reason: String,
+        source_location: SourceLocation,
+    },
+
+    #[error("duplicate sequence participant id `{participant_id}` at {source_location}")]
+    DuplicateParticipantId {
+        participant_id: String,
+        source_location: SourceLocation,
+    },
+
     #[error("participant `{participant}` is used after destroy at {source_location}")]
     DestroyedParticipantUse {
         participant: String,
diff --git a/plantuml/parser/puml_resolver/src/sequence_diagram/src/participant_table.rs b/plantuml/parser/puml_resolver/src/sequence_diagram/src/participant_table.rs
index 854b30b6..56e0d600 100644
--- a/plantuml/parser/puml_resolver/src/sequence_diagram/src/participant_table.rs
+++ b/plantuml/parser/puml_resolver/src/sequence_diagram/src/participant_table.rs
@@ -11,113 +11,238 @@
 // SPDX-License-Identifier: Apache-2.0
 // *******************************************************************************
 
-use std::collections::HashSet;
+use std::collections::{HashMap, HashSet};
 
 use sequence_logic::{
     ParticipantType as LogicParticipantType, SequenceParticipant, SourceLocation,
 };
 use sequence_parser::sequence_ast::{
-    CreateCmd, MessageEndpoint, ParticipantDef, ParticipantIdentifier,
+    CreateCmd, MessageEndpoint, ParticipantDef, ParticipantIdentifier, ParticipantRef,
     ParticipantType as SyntaxParticipantType, Statement,
 };
+use uid_normalization::{InternalScope, RootAnchor};
+use uid_utils::{normalize, normalized_segments};
 
-pub(crate) fn build_participant_table(statements: &[Statement]) -> Vec<SequenceParticipant> {
+use crate::error::SequenceResolverError;
+
+const EXTERNAL_ENDPOINT: &str = "ExternalEndpoint";
+
+#[derive(Debug, Clone, Default)]
+pub(crate) struct ParticipantTable {
+    participants: Vec<SequenceParticipant>,
+    resolved_names: HashMap<String, String>,
+}
+
+impl ParticipantTable {
+    #[cfg(test)]
+    pub(crate) fn participants(&self) -> &[SequenceParticipant] {
+        &self.participants
+    }
+
+    pub(crate) fn into_participants(self) -> Vec<SequenceParticipant> {
+        self.participants
+    }
+
+    pub(crate) fn resolve_identifier(
+        &self,
+        identifier: &ParticipantIdentifier,
+        source_location: &SourceLocation,
+        root_anchor: &RootAnchor,
+    ) -> Result<String, SequenceResolverError> {
+        self.resolve_reference_name(
+            participant_reference_name(identifier),
+            source_location,
+            root_anchor,
+        )
+    }
+
+    pub(crate) fn resolve_participant_ref(
+        &self,
+        participant: &ParticipantRef,
+        source_location: &SourceLocation,
+        root_anchor: &RootAnchor,
+    ) -> Result<String, SequenceResolverError> {
+        self.resolve_reference_name(
+            participant.identifier.as_str(),
+            source_location,
+            root_anchor,
+        )
+    }
+
+    fn resolve_reference_name(
+        &self,
+        reference_name: &str,
+        source_location: &SourceLocation,
+        root_anchor: &RootAnchor,
+    ) -> Result<String, SequenceResolverError> {
+        let normalized_reference = normalize(reference_name);
+
+        if let Some(resolved) = self.resolved_names.get(&normalized_reference) {
+            return Ok(resolved.clone());
+        }
+
+        resolve_selected_participant_uid(reference_name, source_location, root_anchor)
+    }
+}
+
+pub(crate) fn build_participant_table(
+    statements: &[Statement],
+    root_anchor: &RootAnchor,
+) -> Result<ParticipantTable, SequenceResolverError> {
     let mut resolved_names = HashSet::new();
-    let mut participants = Vec::new();
+    let mut resolved_uids = HashSet::new();
+    let mut table = ParticipantTable::default();
 
-    add_explicit_participants(statements, &mut participants, &mut resolved_names);
+    add_explicit_participants(
+        statements,
+        &mut table,
+        &mut resolved_names,
+        &mut resolved_uids,
+        root_anchor,
+    )?;
 
     // Message endpoints and create commands must share the ordered pass so the
     // first participant reference keeps its source location.
-    add_implicit_participants(statements, &mut participants, &mut resolved_names);
-
-    participants
+    add_implicit_participants(
+        statements,
+        &mut table,
+        &mut resolved_names,
+        &mut resolved_uids,
+        root_anchor,
+    )?;
+
+    Ok(table)
 }
 
 fn add_explicit_participants(
     statements: &[Statement],
-    participants: &mut Vec<SequenceParticipant>,
+    table: &mut ParticipantTable,
     resolved_names: &mut HashSet<String>,
-) {
+    resolved_uids: &mut HashSet<String>,
+    root_anchor: &RootAnchor,
+) -> Result<(), SequenceResolverError> {
     for stmt in statements {
         if let Statement::ParticipantDef(participant_def) = stmt {
             add_participant(
-                participants,
+                table,
                 resolved_names,
+                resolved_uids,
                 explicit_participant(participant_def),
-            );
+                root_anchor,
+            )?;
         }
     }
+
+    Ok(())
 }
 
 fn add_implicit_participants(
     statements: &[Statement],
-    participants: &mut Vec<SequenceParticipant>,
+    table: &mut ParticipantTable,
     resolved_names: &mut HashSet<String>,
-) {
+    resolved_uids: &mut HashSet<String>,
+    root_anchor: &RootAnchor,
+) -> Result<(), SequenceResolverError> {
     for stmt in statements {
         match stmt {
             Statement::Message(msg) => {
                 add_endpoint_participant(
-                    participants,
+                    table,
                     resolved_names,
+                    resolved_uids,
                     &msg.left,
                     &msg.source_location,
-                );
+                    root_anchor,
+                )?;
                 add_endpoint_participant(
-                    participants,
+                    table,
                     resolved_names,
+                    resolved_uids,
                     &msg.right,
                     &msg.source_location,
-                );
+                    root_anchor,
+                )?;
             }
             Statement::CreateCmd(create_cmd) => {
                 add_participant(
-                    participants,
+                    table,
                     resolved_names,
+                    resolved_uids,
                     created_participant(create_cmd),
-                );
+                    root_anchor,
+                )?;
             }
             _ => {}
         }
     }
+
+    Ok(())
 }
 
 fn add_participant(
-    participants: &mut Vec<SequenceParticipant>,
+    table: &mut ParticipantTable,
     resolved_names: &mut HashSet<String>,
-    participant: SequenceParticipant,
-) {
+    resolved_uids: &mut HashSet<String>,
+    mut participant: SequenceParticipant,
+    root_anchor: &RootAnchor,
+) -> Result<(), SequenceResolverError> {
     let identifier = ParticipantIdentifier {
         display_name: participant.display_name.clone(),
         alias: participant.alias.clone(),
     };
-    let reference_name = participant_reference_name(&identifier);
-    if reference_name.is_empty() || !resolved_names.insert(reference_name.to_string()) {
-        return;
+    let reference_name = normalized_participant_reference_name(&identifier);
+
+    if reference_name.is_empty() {
+        return Ok(());
+    }
+
+    if !resolved_names.insert(reference_name.clone()) {
+        return Ok(());
     }
-    participants.push(participant);
+
+    let resolved_uid =
+        resolve_participant_identifier_uid(&identifier, &participant.source_location, root_anchor)?;
+
+    if !resolved_uids.insert(resolved_uid.clone()) {
+        return Err(SequenceResolverError::DuplicateParticipantId {
+            participant_id: resolved_uid,
+            source_location: participant.source_location.clone(),
+        });
+    }
+
+    participant.uid = resolved_uid.clone();
+    table.resolved_names.insert(reference_name, resolved_uid);
+    table.participants.push(participant);
+
+    Ok(())
 }
 
 fn add_endpoint_participant(
-    participants: &mut Vec<SequenceParticipant>,
+    table: &mut ParticipantTable,
     resolved_names: &mut HashSet<String>,
+    resolved_uids: &mut HashSet<String>,
     endpoint: &MessageEndpoint,
     source_location: &SourceLocation,
-) {
+    root_anchor: &RootAnchor,
+) -> Result<(), SequenceResolverError> {
     if let MessageEndpoint::Participant(identifier) = endpoint {
         add_participant(
-            participants,
+            table,
             resolved_names,
+            resolved_uids,
             implicit_participant(identifier, source_location),
-        );
+            root_anchor,
+        )?;
     }
+
+    Ok(())
 }
 
 fn explicit_participant(participant_def: &ParticipantDef) -> SequenceParticipant {
     SequenceParticipant {
         display_name: participant_def.identifier.display_name.clone(),
         alias: participant_def.identifier.alias.clone(),
+        uid: String::new(),
         participant_type: map_parser_participant_type(&participant_def.participant_type),
         source_location: participant_def.source_location.clone(),
         stereotype: participant_def.stereotype.clone(),
@@ -128,6 +253,7 @@ fn created_participant(create_cmd: &CreateCmd) -> SequenceParticipant {
     SequenceParticipant {
         display_name: create_cmd.identifier.display_name.clone(),
         alias: create_cmd.identifier.alias.clone(),
+        uid: String::new(),
         participant_type: map_parser_participant_type(&create_cmd.participant_type),
         source_location: create_cmd.source_location.clone(),
         stereotype: create_cmd.stereotype.clone(),
@@ -141,6 +267,7 @@ fn implicit_participant(
     SequenceParticipant {
         display_name: identifier.display_name.clone(),
         alias: identifier.alias.clone(),
+        uid: String::new(),
         participant_type: LogicParticipantType::Participant,
         source_location: source_location.clone(),
         stereotype: None,
@@ -167,6 +294,131 @@ pub(crate) fn participant_reference_name(identifier: &ParticipantIdentifier) ->
         .unwrap_or(&identifier.display_name)
 }
 
+pub(crate) fn normalized_participant_reference_name(identifier: &ParticipantIdentifier) -> String {
+    normalize(participant_reference_name(identifier))
+}
+
+fn resolve_participant_identifier_uid(
+    identifier: &ParticipantIdentifier,
+    source_location: &SourceLocation,
+    root_anchor: &RootAnchor,
+) -> Result<String, SequenceResolverError> {
+    let selected_text = select_participant_uid_text(identifier, source_location)?;
+    resolve_selected_participant_uid(&selected_text, source_location, root_anchor)
+}
+
+fn resolve_selected_participant_uid(
+    selected_text: &str,
+    source_location: &SourceLocation,
+    root_anchor: &RootAnchor,
+) -> Result<String, SequenceResolverError> {
+    let normalized = normalize(selected_text);
+
+    if normalized == EXTERNAL_ENDPOINT {
+        return Ok(EXTERNAL_ENDPOINT.to_string());
+    }
+
+    let parts = normalized_segments(&normalized);
+
+    let Some((leaf, internal_scope)) = parts.split_last() else {
+        return Err(SequenceResolverError::InvalidParticipantIdentifier {
+            participant: selected_text.to_string(),
+            reason: "resolved uid is empty".to_string(),
+            source_location: source_location.clone(),
+        });
+    };
+
+    Ok(
+        InternalScope::new(internal_scope.iter().map(String::as_str))
+            .resolve_with_leaf(root_anchor, leaf),
+    )
+}
+
+fn select_participant_uid_text(
+    identifier: &ParticipantIdentifier,
+    source_location: &SourceLocation,
+) -> Result<String, SequenceResolverError> {
+    let first_line = identifier
+        .display_name
+        .lines()
+        .map(str::trim)
+        .find(|line| !line.is_empty())
+        .unwrap_or_default();
+
+    let standalone_colons = standalone_colon_positions(first_line);
+
+    if standalone_colons.len() > 1 {
+        return Err(SequenceResolverError::InvalidParticipantIdentifier {
+            participant: identifier.display_name.clone(),
+            reason: "multiple standalone ':' separators are not allowed".to_string(),
+            source_location: source_location.clone(),
+        });
+    }
+
+    if let Some(colon_index) = standalone_colons.first().copied() {
+        let rhs = first_line[colon_index + 1..].trim();
+        if rhs.is_empty() {
+            return Err(SequenceResolverError::InvalidParticipantIdentifier {
+                participant: identifier.display_name.clone(),
+                reason: "standalone ':' must have a non-empty right-hand side".to_string(),
+                source_location: source_location.clone(),
+            });
+        }
+        return Ok(rhs.to_string());
+    }
+
+    if is_bare_participant_identifier(first_line) {
+        return Ok(first_line.to_string());
+    }
+
+    if let Some(alias) = identifier.alias.as_deref() {
+        return Ok(alias.to_string());
+    }
+
+    Err(SequenceResolverError::InvalidParticipantIdentifier {
+        participant: identifier.display_name.clone(),
+        reason: "free-text participant display names require an alias for uid derivation"
+            .to_string(),
+        source_location: source_location.clone(),
+    })
+}
+
+fn standalone_colon_positions(text: &str) -> Vec<usize> {
+    let bytes = text.as_bytes();
+    let mut positions = Vec::new();
+
+    for (index, byte) in bytes.iter().enumerate() {
+        if *byte != b':' {
+            continue;
+        }
+
+        let prev_is_colon = index > 0 && bytes[index - 1] == b':';
+        let next_is_colon = index + 1 < bytes.len() && bytes[index + 1] == b':';
+
+        if !prev_is_colon && !next_is_colon {
+            positions.push(index);
+        }
+    }
+
+    positions
+}
+
+fn is_bare_participant_identifier(text: &str) -> bool {
+    if text.is_empty() || text.chars().any(char::is_whitespace) {
+        return false;
+    }
+
+    let segments = normalized_segments(text);
+    !segments.is_empty()
+        && segments
+            .iter()
+            .all(|segment| segment.chars().all(is_identifier_char))
+}
+
+fn is_identifier_char(ch: char) -> bool {
+    ch.is_ascii_alphanumeric() || ch == '_'
+}
+
 #[cfg(test)]
 mod participant_table_tests {
     use super::*;
@@ -177,6 +429,10 @@ mod participant_table_tests {
         SourceLocation::new("test.puml", line)
     }
 
+    fn root_anchor() -> RootAnchor {
+        RootAnchor::new(None)
+    }
+
     fn message_endpoint(name: &str) -> MessageEndpoint {
         MessageEndpoint::Participant(ParticipantIdentifier {
             display_name: name.to_string(),
@@ -237,11 +493,12 @@ mod participant_table_tests {
             message("B", "A", source(2)),
         ];
 
-        let participants = build_participant_table(&statements);
+        let participants = build_participant_table(&statements, &root_anchor())
+            .expect("participant table must build");
 
-        assert_eq!(participants.len(), 2);
-        assert_eq!(participants[0].display_name, "A");
-        assert_eq!(participants[1].display_name, "B");
+        assert_eq!(participants.participants().len(), 2);
+        assert_eq!(participants.participants()[0].display_name, "A");
+        assert_eq!(participants.participants()[1].display_name, "B");
     }
 
     #[test]
@@ -252,37 +509,76 @@ mod participant_table_tests {
             message("A", "B", source(1)),
         ];
 
-        let participants = build_participant_table(&statements);
+        let participants = build_participant_table(&statements, &root_anchor())
+            .expect("participant table must build");
 
-        assert_eq!(participants.len(), 2);
-        assert_eq!(participants[1].display_name, "Display B");
-        assert_eq!(participants[1].alias.as_deref(), Some("B"));
+        assert_eq!(participants.participants().len(), 2);
+        assert_eq!(participants.participants()[1].display_name, "Display B");
+        assert_eq!(participants.participants()[1].alias.as_deref(), Some("B"));
     }
 
     #[test]
-    fn aliased_participant_display_name_reference_creates_implicit_participant() {
+    fn aliased_participant_display_name_reference_is_rejected() {
         let statements = vec![
             participant("A"),
             participant_with_alias("Display B", "B"),
             message("A", "Display B", source(1)),
         ];
 
-        let participants = build_participant_table(&statements);
+        let err = build_participant_table(&statements, &root_anchor())
+            .expect_err("free-text display name references without aliases must fail");
 
-        assert_eq!(participants.len(), 3);
-        assert_eq!(participants[2].display_name, "Display B");
-        assert_eq!(participants[2].alias, None);
+        assert!(matches!(
+            err,
+            SequenceResolverError::InvalidParticipantIdentifier { .. }
+        ));
+    }
+
+    #[test]
+    fn qualified_aliases_are_deduplicated_after_normalization() {
+        let statements = vec![
+            participant_with_alias("Service", "score::logging::Service"),
+            message("Caller", "score.logging.Service", source(1)),
+        ];
+
+        let participants = build_participant_table(&statements, &root_anchor())
+            .expect("participant table must build");
+
+        assert_eq!(participants.participants().len(), 2);
+        assert_eq!(
+            participants.participants()[0].alias.as_deref(),
+            Some("score::logging::Service")
+        );
+        assert_eq!(participants.participants()[1].display_name, "Caller");
+    }
+
+    #[test]
+    fn duplicate_resolved_participant_ids_are_rejected() {
+        let statements = vec![
+            participant_with_alias("svc:billing::InvoiceService", "inv1"),
+            participant_with_alias("billing::InvoiceService", "inv2"),
+        ];
+
+        let err = build_participant_table(&statements, &root_anchor())
+            .expect_err("duplicate resolved participant ids must fail");
+
+        assert!(matches!(
+            err,
+            SequenceResolverError::DuplicateParticipantId { ref participant_id, .. }
+                if participant_id == "billing.InvoiceService"
+        ));
     }
 
     #[test]
     fn no_participants_declared_creates_implicit_participants() {
         let statements = vec![message("X", "Y", source(1))];
 
-        let participants = build_participant_table(&statements);
+        let participants = build_participant_table(&statements, &root_anchor())
+            .expect("participant table must build");
 
-        assert_eq!(participants.len(), 2);
-        assert_eq!(participants[0].display_name, "X");
-        assert_eq!(participants[1].display_name, "Y");
+        assert_eq!(participants.participants().len(), 2);
+        assert_eq!(participants.participants()[0].display_name, "X");
+        assert_eq!(participants.participants()[1].display_name, "Y");
     }
 
     #[test]
@@ -302,13 +598,20 @@ mod participant_table_tests {
             }),
         ];
 
-        let participants = build_participant_table(&statements);
+        let participants = build_participant_table(&statements, &root_anchor())
+            .expect("participant table must build");
 
-        assert_eq!(participants.len(), 2);
-        assert_eq!(participants[0].display_name, "A");
-        assert_eq!(participants[0].source_location, message_location);
-        assert_eq!(participants[1].display_name, "B");
-        assert_eq!(participants[1].source_location, message_location);
+        assert_eq!(participants.participants().len(), 2);
+        assert_eq!(participants.participants()[0].display_name, "A");
+        assert_eq!(
+            participants.participants()[0].source_location,
+            message_location
+        );
+        assert_eq!(participants.participants()[1].display_name, "B");
+        assert_eq!(
+            participants.participants()[1].source_location,
+            message_location
+        );
     }
 
     #[test]
@@ -320,8 +623,88 @@ mod participant_table_tests {
             source_location: source(1),
         })];
 
-        let participants = build_participant_table(&statements);
+        let participants = build_participant_table(&statements, &root_anchor())
+            .expect("participant table must build");
+
+        assert!(participants.participants().is_empty());
+    }
+
+    #[test]
+    fn qualified_display_name_resolves_to_type_text_uid() {
+        let identifier = ParticipantIdentifier {
+            display_name: "core::service::ResourceBuilder".to_string(),
+            alias: Some("Builder".to_string()),
+        };
+
+        let uid = resolve_participant_identifier_uid(&identifier, &source(1), &root_anchor())
+            .expect("uid must resolve");
+
+        assert_eq!(uid, "core.service.ResourceBuilder");
+    }
+
+    #[test]
+    fn single_standalone_colon_uses_rhs_as_type_text() {
+        let identifier = ParticipantIdentifier {
+            display_name: "svc : core::runtime::Service".to_string(),
+            alias: Some("Service".to_string()),
+        };
+
+        let uid = resolve_participant_identifier_uid(&identifier, &source(1), &root_anchor())
+            .expect("uid must resolve");
+
+        assert_eq!(uid, "core.runtime.Service");
+    }
+
+    #[test]
+    fn multiple_standalone_colons_are_rejected() {
+        let identifier = ParticipantIdentifier {
+            display_name: "svc : core::runtime : Service".to_string(),
+            alias: Some("Service".to_string()),
+        };
+
+        let err = resolve_participant_identifier_uid(&identifier, &source(1), &root_anchor())
+            .expect_err("multiple standalone colons must fail");
+
+        assert!(matches!(
+            err,
+            SequenceResolverError::InvalidParticipantIdentifier { .. }
+        ));
+    }
+
+    #[test]
+    fn free_text_display_name_without_alias_is_rejected() {
+        let identifier = ParticipantIdentifier {
+            display_name: "Display Service".to_string(),
+            alias: None,
+        };
+
+        let err = resolve_participant_identifier_uid(&identifier, &source(1), &root_anchor())
+            .expect_err("free-text display names without alias must fail");
+
+        assert!(matches!(
+            err,
+            SequenceResolverError::InvalidParticipantIdentifier { .. }
+        ));
+    }
+
+    #[test]
+    fn bare_identifiers_without_alias_are_accepted() {
+        let simple = ParticipantIdentifier {
+            display_name: "A".to_string(),
+            alias: None,
+        };
+        let qualified = ParticipantIdentifier {
+            display_name: "score::logging::Service".to_string(),
+            alias: None,
+        };
+
+        let simple_uid = resolve_participant_identifier_uid(&simple, &source(1), &root_anchor())
+            .expect("simple bare identifiers must resolve");
+        let qualified_uid =
+            resolve_participant_identifier_uid(&qualified, &source(2), &root_anchor())
+                .expect("qualified bare identifiers must resolve");
 
-        assert!(participants.is_empty());
+        assert_eq!(simple_uid, "A");
+        assert_eq!(qualified_uid, "score.logging.Service");
     }
 }
diff --git a/plantuml/parser/puml_resolver/src/sequence_diagram/src/sequence_resolver.rs b/plantuml/parser/puml_resolver/src/sequence_diagram/src/sequence_resolver.rs
index 36f9aa65..42a021dd 100644
--- a/plantuml/parser/puml_resolver/src/sequence_diagram/src/sequence_resolver.rs
+++ b/plantuml/parser/puml_resolver/src/sequence_diagram/src/sequence_resolver.rs
@@ -14,6 +14,7 @@
 use resolver_traits::DiagramResolver;
 use sequence_logic::SequenceTree;
 use sequence_parser::SeqPumlDocument;
+use uid_normalization::RootAnchor;
 
 use crate::error::SequenceResolverError;
 use crate::lifecycle_validator::validate_lifecycle_consistency;
@@ -26,7 +27,27 @@ use crate::statement_resolver::build_sequence_tree;
 /// validates lifecycle consistency before assembling the final `SequenceTree`.
 /// The resolver stores no per-document state, so the same instance can resolve
 /// multiple documents safely.
-pub struct SequenceResolver;
+pub struct SequenceResolver {
+    root_anchor: RootAnchor,
+}
+
+impl Default for SequenceResolver {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl SequenceResolver {
+    pub fn new() -> Self {
+        Self::with_root_anchor(None)
+    }
+
+    pub fn with_root_anchor(root_anchor: Option<&str>) -> Self {
+        Self {
+            root_anchor: RootAnchor::new(root_anchor),
+        }
+    }
+}
 
 impl DiagramResolver for SequenceResolver {
     type Document = SeqPumlDocument;
@@ -34,13 +55,14 @@ impl DiagramResolver for SequenceResolver {
     type Error = SequenceResolverError;
 
     fn resolve(&mut self, document: &SeqPumlDocument) -> Result<SequenceTree, Self::Error> {
-        let participants = build_participant_table(&document.statements);
-        let root = build_sequence_tree(&document.statements)?;
+        let participant_table = build_participant_table(&document.statements, &self.root_anchor)?;
+        let root =
+            build_sequence_tree(&document.statements, &participant_table, &self.root_anchor)?;
         validate_lifecycle_consistency(&root)?;
 
         Ok(SequenceTree {
             name: document.name.clone(),
-            participants,
+            participants: participant_table.into_participants(),
             root,
         })
     }
@@ -101,7 +123,7 @@ mod sequence_resolver_tests {
     /// An empty diagram produces an empty SequenceTree.
     #[test]
     fn test_empty_document_yields_empty_tree() {
-        let mut resolver = SequenceResolver;
+        let mut resolver = SequenceResolver::new();
         let doc = SeqPumlDocument {
             name: Some("empty".to_string()),
             statements: vec![],
@@ -124,7 +146,7 @@ mod sequence_resolver_tests {
             statements: stmts,
         };
 
-        let mut resolver = SequenceResolver;
+        let mut resolver = SequenceResolver::new();
         let tree1 = resolver.resolve(&doc1).unwrap();
         let tree2 = resolver.resolve(&doc2).unwrap();
 
diff --git a/plantuml/parser/puml_resolver/src/sequence_diagram/src/statement_resolver.rs b/plantuml/parser/puml_resolver/src/sequence_diagram/src/statement_resolver.rs
index 83f250c5..d95c9e4c 100644
--- a/plantuml/parser/puml_resolver/src/sequence_diagram/src/statement_resolver.rs
+++ b/plantuml/parser/puml_resolver/src/sequence_diagram/src/statement_resolver.rs
@@ -21,9 +21,10 @@ use sequence_logic::{
 use sequence_parser::{
     GroupCmd, Message, MessageEndpoint, MessageSuffix, ParticipantRef, RefCmd, Statement,
 };
+use uid_normalization::RootAnchor;
 
 use crate::error::SequenceResolverError;
-use crate::participant_table::participant_reference_name;
+use crate::participant_table::ParticipantTable;
 use crate::sequence_tree_builder::SequenceTreeBuilder;
 
 #[derive(Debug, Clone, Copy)]
@@ -40,11 +41,13 @@ enum LifecycleTarget {
 
 pub(crate) fn build_sequence_tree(
     statements: &[Statement],
+    participant_table: &ParticipantTable,
+    root_anchor: &RootAnchor,
 ) -> Result<Block, SequenceResolverError> {
     let mut builder = SequenceTreeBuilder::new();
 
     for statement in statements {
-        consume_statement(&mut builder, statement)?;
+        consume_statement(&mut builder, statement, participant_table, root_anchor)?;
     }
 
     builder.finish()
@@ -53,10 +56,12 @@ pub(crate) fn build_sequence_tree(
 fn consume_statement(
     builder: &mut SequenceTreeBuilder,
     statement: &Statement,
+    participant_table: &ParticipantTable,
+    root_anchor: &RootAnchor,
 ) -> Result<(), SequenceResolverError> {
     match statement {
         Statement::Message(message) => {
-            for node in message_nodes(message)? {
+            for node in message_nodes(message, participant_table, root_anchor)? {
                 builder.push(node);
             }
         }
@@ -65,33 +70,54 @@ fn consume_statement(
         Statement::GroupCmd(GroupCmd::End(end)) => builder.end_group(end)?,
         Statement::CreateCmd(create_cmd) => {
             builder.push(lifecycle_node(
-                Arc::<str>::from(participant_reference_name(&create_cmd.identifier)),
+                Arc::<str>::from(participant_table.resolve_identifier(
+                    &create_cmd.identifier,
+                    &create_cmd.source_location,
+                    root_anchor,
+                )?),
                 LifecycleAction::Create,
                 create_cmd.source_location.clone(),
             ));
         }
         Statement::DestroyCmd(destroy_cmd) => {
             builder.push(lifecycle_node(
-                participant_ref_name(&destroy_cmd.participant),
+                participant_ref_name(
+                    &destroy_cmd.participant,
+                    &destroy_cmd.source_location,
+                    participant_table,
+                    root_anchor,
+                )?,
                 LifecycleAction::Destroy,
                 destroy_cmd.source_location.clone(),
             ));
         }
         Statement::ActivateCmd(activate_cmd) => {
             builder.push(lifecycle_node(
-                participant_ref_name(&activate_cmd.participant),
+                participant_ref_name(
+                    &activate_cmd.participant,
+                    &activate_cmd.source_location,
+                    participant_table,
+                    root_anchor,
+                )?,
                 LifecycleAction::Activate,
                 activate_cmd.source_location.clone(),
             ));
         }
         Statement::DeactivateCmd(deactivate_cmd) => {
             builder.push(lifecycle_node(
-                participant_ref_name(&deactivate_cmd.participant),
+                participant_ref_name(
+                    &deactivate_cmd.participant,
+                    &deactivate_cmd.source_location,
+                    participant_table,
+                    root_anchor,
+                )?,
                 LifecycleAction::Deactivate,
                 deactivate_cmd.source_location.clone(),
             ));
         }
-        Statement::RefCmd(ref_cmd) => builder.push(reference_node(ref_cmd)),
+        Statement::RefCmd(ref_cmd) => {
+            builder.push(reference_node(ref_cmd, participant_table, root_anchor)?);
+        }
         Statement::ParticipantDef(_) => {}
         // `return` has no sender or receiver. Modeling it requires a call stack
         // to resolve the matching invocation, which the resolver does not yet maintain.
@@ -101,11 +127,25 @@ fn consume_statement(
     Ok(())
 }
 
-fn message_nodes(message: &Message) -> Result<Vec<Node>, SequenceResolverError> {
+fn message_nodes(
+    message: &Message,
+    participant_table: &ParticipantTable,
+    root_anchor: &RootAnchor,
+) -> Result<Vec<Node>, SequenceResolverError> {
     let (sender, receiver) = directed_endpoints(message)?;
 
-    let sender_name = endpoint_name(sender);
-    let receiver_name = endpoint_name(receiver);
+    let sender_name = endpoint_name(
+        sender,
+        &message.source_location,
+        participant_table,
+        root_anchor,
+    )?;
+    let receiver_name = endpoint_name(
+        receiver,
+        &message.source_location,
+        participant_table,
+        root_anchor,
+    )?;
 
     let lifecycle_ops = collect_message_lifecycle_ops(message.suffix.as_ref());
 
@@ -207,16 +247,27 @@ fn suffix_to_lifecycle(suffix: &MessageSuffix) -> LifecycleOp {
     }
 }
 
-fn reference_node(ref_cmd: &RefCmd) -> Node {
-    Node::Reference(Reference {
+fn reference_node(
+    ref_cmd: &RefCmd,
+    participant_table: &ParticipantTable,
+    root_anchor: &RootAnchor,
+) -> Result<Node, SequenceResolverError> {
+    Ok(Node::Reference(Reference {
         participants: ref_cmd
             .participants
             .iter()
-            .map(participant_ref_name)
-            .collect(),
+            .map(|participant| {
+                participant_ref_name(
+                    participant,
+                    &ref_cmd.source_location,
+                    participant_table,
+                    root_anchor,
+                )
+            })
+            .collect::<Result<Vec<_>, _>>()?,
         text: ref_cmd.text.clone(),
         source_location: ref_cmd.source_location.clone(),
-    })
+    }))
 }
 
 fn lifecycle_node(
@@ -231,17 +282,29 @@ fn lifecycle_node(
     })
 }
 
-fn endpoint_name(endpoint: &MessageEndpoint) -> Option<ParticipantId> {
+fn endpoint_name(
+    endpoint: &MessageEndpoint,
+    source_location: &SourceLocation,
+    participant_table: &ParticipantTable,
+    root_anchor: &RootAnchor,
+) -> Result<Option<ParticipantId>, SequenceResolverError> {
     match endpoint {
-        MessageEndpoint::Participant(identifier) => {
-            Some(Arc::<str>::from(participant_reference_name(identifier)))
-        }
-        MessageEndpoint::LostFound(_) => None,
+        MessageEndpoint::Participant(identifier) => Ok(Some(Arc::<str>::from(
+            participant_table.resolve_identifier(identifier, source_location, root_anchor)?,
+        ))),
+        MessageEndpoint::LostFound(_) => Ok(None),
     }
 }
 
-fn participant_ref_name(participant: &ParticipantRef) -> ParticipantId {
-    Arc::<str>::from(participant.identifier.as_str())
+fn participant_ref_name(
+    participant: &ParticipantRef,
+    source_location: &SourceLocation,
+    participant_table: &ParticipantTable,
+    root_anchor: &RootAnchor,
+) -> Result<ParticipantId, SequenceResolverError> {
+    Ok(Arc::<str>::from(
+        participant_table.resolve_participant_ref(participant, source_location, root_anchor)?,
+    ))
 }
 
 fn directed_endpoints(
@@ -273,7 +336,13 @@ fn directed_endpoints(
 mod message_arrow_tests {
     use super::*;
     use parser_core::common_ast::{Arrow, ArrowDecor, ArrowLine};
-    use sequence_parser::ParticipantIdentifier;
+    use sequence_parser::{
+        sequence_ast::{ParticipantDef, ParticipantType, Statement},
+        ParticipantIdentifier,
+    };
+    use uid_normalization::RootAnchor;
+
+    use crate::participant_table::build_participant_table;
 
     fn arrow(line: &str, right: Option<&str>) -> Arrow {
         Arrow {
@@ -318,12 +387,24 @@ mod message_arrow_tests {
         }
     }
 
+    fn root_anchor() -> RootAnchor {
+        RootAnchor::new(None)
+    }
+
+    fn participant_table_for(statements: &[Statement]) -> ParticipantTable {
+        build_participant_table(statements, &root_anchor()).expect("participant table must build")
+    }
+
     #[test]
     fn test_solid_directed_arrow_produces_interaction() {
         assert_eq!(
-            message_nodes(&message(arrow("-", Some(">"))))
-                .expect("must resolve a directed arrow")
-                .len(),
+            message_nodes(
+                &message(arrow("-", Some(">"))),
+                &participant_table_for(&[]),
+                &root_anchor()
+            )
+            .expect("must resolve a directed arrow")
+            .len(),
             1
         );
     }
@@ -331,9 +412,13 @@ mod message_arrow_tests {
     #[test]
     fn test_dashed_directed_arrow_produces_interaction() {
         assert_eq!(
-            message_nodes(&message(arrow("--", Some(">"))))
-                .expect("must resolve a directed arrow")
-                .len(),
+            message_nodes(
+                &message(arrow("--", Some(">"))),
+                &participant_table_for(&[]),
+                &root_anchor()
+            )
+            .expect("must resolve a directed arrow")
+            .len(),
             1
         );
     }
@@ -362,6 +447,84 @@ mod message_arrow_tests {
         ));
     }
 
+    #[test]
+    fn endpoint_name_normalizes_cpp_qualified_aliases() {
+        let identifier = ParticipantIdentifier {
+            display_name: "Display Service".to_string(),
+            alias: Some("score::logging::Service".to_string()),
+        };
+        let endpoint = MessageEndpoint::Participant(identifier.clone());
+        let participant_table =
+            participant_table_for(&[Statement::ParticipantDef(ParticipantDef {
+                participant_type: ParticipantType::Participant,
+                identifier,
+                stereotype: None,
+                source_location: SourceLocation::new("", 0),
+            })]);
+
+        assert_eq!(
+            endpoint_name(
+                &endpoint,
+                &SourceLocation::new("", 0),
+                &participant_table,
+                &root_anchor()
+            )
+            .expect("endpoint name must resolve")
+            .as_deref(),
+            Some("score.logging.Service")
+        );
+    }
+
+    #[test]
+    fn participant_ref_name_normalizes_cpp_qualified_identifiers() {
+        let participant = ParticipantRef {
+            identifier: "score::logging::Service".to_string(),
+        };
+        let participant_table = participant_table_for(&[]);
+
+        assert_eq!(
+            participant_ref_name(
+                &participant,
+                &SourceLocation::new("", 0),
+                &participant_table,
+                &root_anchor(),
+            )
+            .expect("participant ref must resolve")
+            .as_ref(),
+            "score.logging.Service"
+        );
+    }
+
+    #[test]
+    fn endpoint_name_resolves_alias_to_type_text_uid() {
+        let participant_table =
+            participant_table_for(&[Statement::ParticipantDef(ParticipantDef {
+                participant_type: ParticipantType::Participant,
+                identifier: ParticipantIdentifier {
+                    display_name: "core::service::ResourceBuilder".to_string(),
+                    alias: Some("Builder".to_string()),
+                },
+                stereotype: None,
+                source_location: SourceLocation::new("", 0),
+            })]);
+        let endpoint = MessageEndpoint::Participant(ParticipantIdentifier {
+            display_name: "Builder".to_string(),
+            alias: None,
+        });
+
+        assert_eq!(
+            endpoint_name(
+                &endpoint,
+                &SourceLocation::new("", 0),
+                &participant_table,
+                &root_anchor()
+            )
+            .expect("endpoint name must resolve")
+            .as_deref(),
+            Some("core.service.ResourceBuilder")
+        );
+    }
+
     #[test]
     fn test_lifecycle_suffixes_target_the_correct_message_endpoint() {
         let cases = [
@@ -376,7 +539,12 @@ mod message_arrow_tests {
             let mut suffixed_message = message(arrow("-", Some(">")));
             suffixed_message.suffix = Some(suffix);
 
-            let nodes = message_nodes(&suffixed_message).expect("suffix must resolve");
+            let nodes = message_nodes(
+                &suffixed_message,
+                &participant_table_for(&[]),
+                &root_anchor(),
+            )
+            .expect("suffix must resolve");
             let lifecycle_matches = |lifecycle: &ParticipantLifecycle| {
                 lifecycle.participant.as_ref() == participant && lifecycle.action == action
             };
@@ -410,9 +578,10 @@ mod message_arrow_tests {
         let mut return_message = message(arrow("--", Some(">")));
         return_message.source_location = return_location.clone();
 
-        let root =
-            build_sequence_tree(&[Statement::Message(call), Statement::Message(return_message)])
-                .expect("messages must resolve");
+        let statements = [Statement::Message(call), Statement::Message(return_message)];
+        let participant_table = participant_table_for(&statements);
+        let root = build_sequence_tree(&statements, &participant_table, &root_anchor())
+            .expect("messages must resolve");
 
         assert_eq!(root.items.len(), 2);
         let Node::Interaction(interaction) = &root.items[0] else {
@@ -434,7 +603,12 @@ mod message_arrow_tests {
             MessageSuffix::Activate,
         ]));
 
-        let nodes = message_nodes(&combined_message).expect("combined suffix must resolve");
+        let nodes = message_nodes(
+            &combined_message,
+            &participant_table_for(&[]),
+            &root_anchor(),
+        )
+        .expect("combined suffix must resolve");
         assert!(matches!(
             nodes.as_slice(),
             [
@@ -458,7 +632,12 @@ mod message_arrow_tests {
             MessageSuffix::Activate,
         ]));
 
-        let nodes = message_nodes(&combined_message).expect("combined suffix must resolve");
+        let nodes = message_nodes(
+            &combined_message,
+            &participant_table_for(&[]),
+            &root_anchor(),
+        )
+        .expect("combined suffix must resolve");
         assert!(matches!(
             nodes.as_slice(),
             [
diff --git a/plantuml/parser/puml_resolver/src/sequence_diagram/tests/sequence_resolver_test.rs b/plantuml/parser/puml_resolver/src/sequence_diagram/tests/sequence_resolver_test.rs
index be27c81a..9e843a7d 100644
--- a/plantuml/parser/puml_resolver/src/sequence_diagram/tests/sequence_resolver_test.rs
+++ b/plantuml/parser/puml_resolver/src/sequence_diagram/tests/sequence_resolver_test.rs
@@ -36,7 +36,7 @@ impl DiagramProcessor for SequenceResolverRunner {
     ) -> Result<HashMap<Rc<PathBuf>, SequenceTree>, SequenceResolverError> {
         let mut results = HashMap::new();
         let mut parser = PumlSequenceParser;
-        let mut resolver = SequenceResolver;
+        let mut resolver = SequenceResolver::new();
 
         for path in files {
             let puml_file = fs::read_to_string(&**path).expect("Failed to read test file");
@@ -121,6 +121,16 @@ fn test_invalid_message_direction() {
     run_sequence_resolver_case("invalid_message_direction");
 }
 
+#[test]
+fn test_invalid_free_text_participant_identifier() {
+    run_sequence_resolver_case("invalid_free_text_participant_identifier");
+}
+
+#[test]
+fn test_invalid_duplicate_participant_id() {
+    run_sequence_resolver_case("invalid_duplicate_participant_id");
+}
+
 #[test]
 fn test_invalid_unterminated_group() {
     run_sequence_resolver_case("invalid_unterminated_group");
diff --git a/plantuml/parser/puml_resolver/src/uid_normalization.rs b/plantuml/parser/puml_resolver/src/uid_normalization.rs
new file mode 100644
index 00000000..1768ee9e
--- /dev/null
+++ b/plantuml/parser/puml_resolver/src/uid_normalization.rs
@@ -0,0 +1,248 @@
+// *******************************************************************************
+// Copyright (c) 2026 Contributors to the Eclipse Foundation
+//
+// See the NOTICE file(s) distributed with this work for additional
+// information regarding copyright ownership.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Apache License Version 2.0 which is available at
+// <https://www.apache.org/licenses/LICENSE-2.0>
+//
+// SPDX-License-Identifier: Apache-2.0
+// *******************************************************************************
+
+pub use uid_utils::{join, normalize, normalized_segments};
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct RootAnchor(Option<String>);
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct InternalScope(Vec<String>);
+
+impl RootAnchor {
+    pub fn new(value: Option<&str>) -> Self {
+        Self(
+            value
+                .map(normalize)
+                .filter(|normalized| !normalized.is_empty()),
+        )
+    }
+
+    pub fn as_deref(&self) -> Option<&str> {
+        self.0.as_deref()
+    }
+}
+
+impl InternalScope {
+    pub fn new<I, S>(parts: I) -> Self
+    where
+        I: IntoIterator<Item = S>,
+        S: AsRef<str>,
+    {
+        Self(
+            parts
+                .into_iter()
+                .flat_map(|part| normalized_segments(part.as_ref()))
+                .collect(),
+        )
+    }
+
+    pub fn from_path(value: &str) -> Self {
+        Self(normalized_segments(value))
+    }
+
+    pub fn from_optional_path(value: Option<&str>) -> Self {
+        value.map(Self::from_path).unwrap_or_default()
+    }
+
+    pub fn resolve_with_leaf(&self, root_anchor: &RootAnchor, leaf: &str) -> String {
+        let mut parts = Vec::with_capacity(self.0.len() + 2);
+
+        if let Some(root_anchor) = root_anchor.as_deref() {
+            parts.push(root_anchor.to_string());
+        }
+
+        parts.extend(self.0.iter().cloned());
+        parts.push(normalize(leaf));
+
+        join(parts)
+    }
+
+    pub fn resolve(&self, root_anchor: &RootAnchor) -> String {
+        join(
+            root_anchor
+                .as_deref()
+                .into_iter()
+                .chain(self.0.iter().map(String::as_str)),
+        )
+    }
+}
+
+pub fn resolve_explicit_path(root_anchor: &RootAnchor, path: &str) -> String {
+    let normalized_path = normalize(path);
+
+    internal_scope_from_resolved_path(root_anchor, Some(normalized_path.as_str()))
+        .resolve(root_anchor)
+}
+
+pub fn internal_scope_from_resolved_path(
+    root_anchor: &RootAnchor,
+    path: Option<&str>,
+) -> InternalScope {
+    match path {
+        Some(path) => {
+            let unrooted_path = root_anchor
+                .as_deref()
+                .and_then(|root| strip_root_anchor_prefix(path, root))
+                .map(|rest| rest.trim_start_matches('.'))
+                .unwrap_or(path);
+
+            InternalScope::from_path(unrooted_path)
+        }
+        None => InternalScope::default(),
+    }
+}
+
+fn strip_root_anchor_prefix<'a>(path: &'a str, root: &str) -> Option<&'a str> {
+    if path == root {
+        return Some("");
+    }
+
+    path.strip_prefix(root)?.strip_prefix('.')
+}
+
+pub fn is_explicit_path(value: &str) -> bool {
+    value.contains('.') || value.contains("::")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{
+        internal_scope_from_resolved_path, is_explicit_path, join, normalize, normalized_segments,
+        resolve_explicit_path, InternalScope, RootAnchor,
+    };
+
+    #[test]
+    fn normalize_treats_cpp_and_dot_separators_equally() {
+        assert_eq!(
+            normalize("score::mw.log::Recorder"),
+            "score.mw.log.Recorder"
+        );
+    }
+
+    #[test]
+    fn normalize_drops_leading_and_trailing_dots() {
+        assert_eq!(normalize("..score::mw::log.."), "score.mw.log");
+    }
+
+    #[test]
+    fn normalized_segments_drops_empty_segments_after_normalization() {
+        assert_eq!(
+            normalized_segments("..score::mw.log::Recorder.."),
+            vec!["score", "mw", "log", "Recorder"]
+        );
+    }
+
+    #[test]
+    fn join_skips_empty_segments() {
+        assert_eq!(
+            join(["root", "", "domain", "Controller"]),
+            "root.domain.Controller"
+        );
+    }
+
+    #[test]
+    fn join_returns_empty_string_when_all_segments_are_empty() {
+        assert!(join(["", "", ""]).is_empty());
+    }
+
+    #[test]
+    fn root_anchor_normalizes_and_retains_non_empty_values() {
+        assert_eq!(
+            RootAnchor::new(Some("score::logging")).as_deref(),
+            Some("score.logging")
+        );
+    }
+
+    #[test]
+    fn root_anchor_drops_empty_values_after_normalization() {
+        assert_eq!(RootAnchor::new(Some("::")).as_deref(), None);
+        assert_eq!(RootAnchor::new(None).as_deref(), None);
+    }
+
+    #[test]
+    fn internal_scope_normalizes_each_segment() {
+        let scope = InternalScope::new(["score::logging", "", ".core."]);
+
+        assert_eq!(scope, InternalScope::from_path("score.logging.core"));
+    }
+
+    #[test]
+    fn internal_scope_resolves_with_leaf_and_root_anchor() {
+        let root_anchor = RootAnchor::new(Some("score::logging"));
+        let scope = InternalScope::new(["component", "subsystem"]);
+
+        assert_eq!(
+            scope.resolve_with_leaf(&root_anchor, "Recorder"),
+            "score.logging.component.subsystem.Recorder"
+        );
+    }
+
+    #[test]
+    fn resolve_explicit_path_prefixes_root_anchor() {
+        let root_anchor = RootAnchor::new(Some("score::logging"));
+
+        assert_eq!(
+            resolve_explicit_path(&root_anchor, "core::Recorder"),
+            "score.logging.core.Recorder"
+        );
+    }
+
+    #[test]
+    fn resolve_explicit_path_does_not_double_prefix_rooted_paths() {
+        let root_anchor = RootAnchor::new(Some("score::logging"));
+
+        assert_eq!(
+            resolve_explicit_path(&root_anchor, "score::logging::Recorder"),
+            "score.logging.Recorder"
+        );
+    }
+
+    #[test]
+    fn internal_scope_from_resolved_path_strips_root_anchor_prefix() {
+        let root_anchor = RootAnchor::new(Some("score::logging"));
+
+        assert_eq!(
+            internal_scope_from_resolved_path(
+                &root_anchor,
+                Some("score.logging.package_a.InternalInterface"),
+            ),
+            InternalScope::from_path("package_a.InternalInterface")
+        );
+    }
+
+    #[test]
+    fn internal_scope_from_resolved_path_keeps_unrooted_paths() {
+        let root_anchor = RootAnchor::new(Some("score::logging"));
+
+        assert_eq!(
+            internal_scope_from_resolved_path(&root_anchor, Some("package_a.InternalInterface")),
+            InternalScope::from_path("package_a.InternalInterface")
+        );
+        assert_eq!(
+            internal_scope_from_resolved_path(&root_anchor, Some("score.logginging.Component")),
+            InternalScope::from_path("score.logginging.Component")
+        );
+        assert_eq!(
+            internal_scope_from_resolved_path(&root_anchor, None),
+            InternalScope::default()
+        );
+    }
+
+    #[test]
+    fn is_explicit_path_accepts_cpp_and_dot_qualified_names() {
+        assert!(is_explicit_path("score::mw::log::Recorder"));
+        assert!(is_explicit_path("score.mw.log.Recorder"));
+        assert!(!is_explicit_path("Recorder"));
+    }
+}
diff --git a/tools/metamodel/common/BUILD b/tools/metamodel/common/BUILD
index ac233eb1..34bc447a 100644
--- a/tools/metamodel/common/BUILD
+++ b/tools/metamodel/common/BUILD
@@ -10,7 +10,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
-load("@rules_rust//rust:defs.bzl", "rust_library")
+load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -24,3 +24,16 @@ rust_library(
         "@crates//:serde",
     ],
 )
+
+rust_library(
+    name = "uid_utils",
+    srcs = ["uid_utils.rs"],
+    crate_name = "uid_utils",
+    crate_root = "uid_utils.rs",
+    edition = "2021",
+)
+
+rust_test(
+    name = "uid_utils_unit_test",
+    crate = ":uid_utils",
+)
diff --git a/tools/metamodel/common/uid_utils.rs b/tools/metamodel/common/uid_utils.rs
new file mode 100644
index 00000000..5e7e69ff
--- /dev/null
+++ b/tools/metamodel/common/uid_utils.rs
@@ -0,0 +1,76 @@
+// *******************************************************************************
+// Copyright (c) 2026 Contributors to the Eclipse Foundation
+//
+// See the NOTICE file(s) distributed with this work for additional
+// information regarding copyright ownership.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Apache License Version 2.0 which is available at
+// <https://www.apache.org/licenses/LICENSE-2.0>
+//
+// SPDX-License-Identifier: Apache-2.0
+// *******************************************************************************
+
+pub fn normalize(value: &str) -> String {
+    value.replace("::", ".").trim_matches('.').to_string()
+}
+
+pub fn normalized_segments(value: &str) -> Vec<String> {
+    normalize(value)
+        .split('.')
+        .filter(|part| !part.is_empty())
+        .map(str::to_string)
+        .collect()
+}
+
+pub fn join<I, S>(parts: I) -> String
+where
+    I: IntoIterator<Item = S>,
+    S: AsRef<str>,
+{
+    parts
+        .into_iter()
+        .map(|part| part.as_ref().to_string())
+        .filter(|part| !part.is_empty())
+        .collect::<Vec<_>>()
+        .join(".")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{join, normalize, normalized_segments};
+
+    #[test]
+    fn normalize_treats_cpp_and_dot_separators_equally() {
+        assert_eq!(
+            normalize("score::mw.log::Recorder"),
+            "score.mw.log.Recorder"
+        );
+    }
+
+    #[test]
+    fn normalize_drops_leading_and_trailing_dots() {
+        assert_eq!(normalize("..score::mw::log.."), "score.mw.log");
+    }
+
+    #[test]
+    fn normalized_segments_drops_empty_segments_after_normalization() {
+        assert_eq!(
+            normalized_segments("..score::mw.log::Recorder.."),
+            vec!["score", "mw", "log", "Recorder"]
+        );
+    }
+
+    #[test]
+    fn join_skips_empty_segments() {
+        assert_eq!(
+            join(["root", "", "domain", "Controller"]),
+            "root.domain.Controller"
+        );
+    }
+
+    #[test]
+    fn join_returns_empty_string_when_all_segments_are_empty() {
+        assert!(join(["", "", ""]).is_empty());
+    }
+}
diff --git a/tools/metamodel/sequence/sequence_logic.rs b/tools/metamodel/sequence/sequence_logic.rs
index 4e8ce86c..46277189 100644
--- a/tools/metamodel/sequence/sequence_logic.rs
+++ b/tools/metamodel/sequence/sequence_logic.rs
@@ -165,6 +165,8 @@ pub enum ParticipantType {
 pub struct SequenceParticipant {
     pub display_name: String,
     pub alias: Option<String>,
+    #[serde(default)]
+    pub uid: String,
     pub participant_type: ParticipantType,
     pub source_location: SourceLocation,
     pub stereotype: Option<String>,
diff --git a/tools/serialization/flatbuffers/sequence/sequence_diagram.fbs b/tools/serialization/flatbuffers/sequence/sequence_diagram.fbs
index dfabca00..1ee31711 100644
--- a/tools/serialization/flatbuffers/sequence/sequence_diagram.fbs
+++ b/tools/serialization/flatbuffers/sequence/sequence_diagram.fbs
@@ -55,6 +55,8 @@ table SequenceParticipant {
     display_name: string (required);
     /// Optional alias used for references in messages
     alias: string;
+    /// Resolver-generated participant uid derived by normalization/root anchor rules
+    uid: string;
     /// Participant kind (participant, actor, boundary, ...)
     participant_type: ParticipantType = Participant;
     /// Source location of the declaration, when available
diff --git a/tools/serialization/flatbuffers/sequence/sequence_serializer.rs b/tools/serialization/flatbuffers/sequence/sequence_serializer.rs
index ea6e5b42..e770b413 100644
--- a/tools/serialization/flatbuffers/sequence/sequence_serializer.rs
+++ b/tools/serialization/flatbuffers/sequence/sequence_serializer.rs
@@ -73,6 +73,11 @@ impl SequenceSerializer {
             .alias
             .as_deref()
             .map(|value| builder.create_string(value));
+        let uid = if participant.uid.is_empty() {
+            None
+        } else {
+            Some(builder.create_string(&participant.uid))
+        };
         let stereotype = participant
             .stereotype
             .as_deref()
@@ -91,6 +96,7 @@ impl SequenceSerializer {
             &fb::SequenceParticipantArgs {
                 display_name: Some(display_name),
                 alias,
+                uid,
                 participant_type: map_participant_type(&participant.participant_type),
                 source_location: Some(source_location),
                 stereotype,
diff --git a/validation/core/BUILD b/validation/core/BUILD
index 160b0aba..b3ba9279 100644
--- a/validation/core/BUILD
+++ b/validation/core/BUILD
@@ -67,6 +67,7 @@ rust_library(
         "src/validators/mod.rs",
         "src/validators/sequence_internal_api_validator.rs",
         "src/validators/shared/diagram_analysis.rs",
+        "src/validators/shared/display.rs",
         "src/validators/shared/helpers.rs",
         "src/validators/shared/mod.rs",
         "src/validators/test/class_design_sequence_validator_test.rs",
@@ -81,6 +82,7 @@ rust_library(
     deps = [
         "//tools/metamodel/class:class_diagram",
         "//tools/metamodel/common:source_location",
+        "//tools/metamodel/common:uid_utils",
         "//tools/metamodel/component:component_diagram",
         "//tools/metamodel/sequence:sequence_diagram",
         "//tools/serialization/flatbuffers/class:class_fbs",
diff --git a/validation/core/README.md b/validation/core/README.md
index 0aff1224..93aa7d93 100644
--- a/validation/core/README.md
+++ b/validation/core/README.md
@@ -31,9 +31,9 @@ The current implementation supports these validation flows:
    PlantUML component-diagram structure.
 2. `ComponentInternalApi`: checks that every component-diagram interface is
   declared by the Internal API diagram.
-3. `ComponentSequence`: checks that component-diagram unit aliases, shared
-  interface relations, and sequence-diagram function-call connections stay in
-  sync.
+3. `ComponentSequence`: checks that component-diagram unit ids, shared
+  interface relations, and sequence-diagram participant/function-call
+  connections stay in sync.
 4. `SequenceInternalApi`: checks that Internal API methods are exercised by
   sequence interactions. When component input is also available, it uses that
   component context to check sequence function names against related shared
diff --git a/validation/core/docs/requirements/tool_requirements.trlc b/validation/core/docs/requirements/tool_requirements.trlc
index 43fa3c04..a1dbf819 100644
--- a/validation/core/docs/requirements/tool_requirements.trlc
+++ b/validation/core/docs/requirements/tool_requirements.trlc
@@ -109,12 +109,12 @@ section "Tool Requirements" {
 
         section "Component Sequence Validator" {
 
-            ToolQualification.ToolRequirement ComponentSequenceAliasConsistency {
+            ToolQualification.ToolRequirement ComponentSequenceIdentifierConsistency {
                 description = '''The validator shall report an error when a
-                unit alias defined in the component diagram does not appear
-                among the participants in any sequence diagram, or when a
-                participant alias in a sequence diagram does not match any
-                unit alias in the component diagram.'''
+                unit id defined in the component diagram does not appear as a
+                participant uid in any sequence diagram, or when a participant
+                uid in a sequence diagram does not match any unit id in the
+                component diagram.'''
                 derived_from = [UseCases.Validate_Architecture_Specification_Documents]
                 satisfied_by = Verifier
             }
@@ -291,9 +291,9 @@ section "Tool Requirements" {
             ToolQualification.ToolRequirement ClassDesignSequenceParticipantClassConsistency {
                 description = '''The validator shall report an error when a
                 sequence participant that represents a designed runtime
-                element has no matching class in the unit design class
-                diagram, or when the participant matches multiple design
-                classes ambiguously.'''
+                element does not provide a valid class identifier for
+                class-design validation, or when it has no matching class
+                in the unit design class diagram.'''
                 derived_from = [UseCases.Validate_Unit_Specification_Documents]
                 satisfied_by = Verifier
             }
diff --git a/validation/core/docs/specifications/class_design_implementation.md b/validation/core/docs/specifications/class_design_implementation.md
index ef419bcd..0f7eedde 100644
--- a/validation/core/docs/specifications/class_design_implementation.md
+++ b/validation/core/docs/specifications/class_design_implementation.md
@@ -263,14 +263,14 @@ Before comparing types, the validator applies limited normalization.
 | `std::uint8_t` | `uint8_t` |
 | `uint8_t *` | `uint8_t*` |
 | `Payload &` | `Payload&` |
-| `vehicle.Engine` | `vehicle::Engine` |
-
-The last row accounts for a difference between the class diagram and
-implementation parser UIDs: dots used as namespace separators are converted to
-`::` before comparison. This applies to type names, class/entity IDs, and
-relationship source/target identifiers alike. cv-qualifiers such as `const`
-and `volatile`, and the pointer/reference decorators `*`/`&`, are preserved
-(only the spacing around them is normalized).
+| `vehicle::Engine` | `vehicle.Engine` |
+
+The last row canonicalizes implementation-side C++ namespace separators to the
+same dot-separated UID form used by class diagrams and root anchors. This
+applies to type names, class/entity IDs, and relationship source/target
+identifiers alike. cv-qualifiers such as `const` and `volatile`, and the
+pointer/reference decorators `*`/`&`, are preserved (only the spacing around
+them is normalized).
 
 ## Failure Cases
 
diff --git a/validation/core/docs/specifications/class_design_sequence.md b/validation/core/docs/specifications/class_design_sequence.md
index b109744c..e051cce6 100644
--- a/validation/core/docs/specifications/class_design_sequence.md
+++ b/validation/core/docs/specifications/class_design_sequence.md
@@ -50,34 +50,12 @@ to exactly one class in the design class model.
 This check validates that the sequence does not reference unknown or ambiguous
 classes.
 
-Participant resolution shall follow this order:
-
-1. Match the participant reference itself against a class id.
-2. If the participant has a different display name, match that display name
-  against a class id.
-3. If the display name still does not resolve, match the display name against a
-  unique class short name.
-4. If the display name uses one supported special form, derive additional class
-  candidates from that form.
-5. If none of the above resolves uniquely, fall back to matching the
-  participant reference against a unique class short name.
-
-The supported special display forms are:
-
-- `:Name`, which contributes `Name` as a short-name candidate.
-- `prefix:qualified::Type`, which contributes `qualified::Type` as an id
-  candidate and both `qualified::Type` and `Type` as short-name candidates.
-
-Only the first non-empty display line participates in class matching. If the
-display name contains additional non-empty lines or escaped line fragments
-after the primary line, they shall be ignored for matching and may be reported
-through debug or warning output.
-
-The following participant display forms are invalid and shall be rejected as
-participant-class failures:
-
-- a primary display line containing more than one standalone `:` separator
-- a primary display line containing `:` without a non-empty right-hand side
+Participant resolution matches the participant reference against a class id.
+The participant must therefore provide a valid class identifier for
+class-design validation.
+The validator may normalize namespace formatting differences emitted by the
+parser, such as `qualified::Type` versus `qualified.Type`, but it does not use
+participant display names or short-name fallback matching.
 
 ```text
 ' class diagram
@@ -146,9 +124,8 @@ Controller -> Controller : Validate()
 
 | Failure case | Validation rule |
 |---|---|
+| Sequence participant does not provide a valid class identifier | Participant-Class Consistency |
 | Sequence participant has no matching design class | Participant-Class Consistency |
-| Sequence participant matches multiple design classes ambiguously | Participant-Class Consistency |
-| Sequence participant uses a disallowed special display form | Participant-Class Consistency |
 | Sequence message targets a class that does not declare or accessibly inherit the called operation | Message-Operation Consistency |
 | Sequence self-call targets a class that does not declare or accessibly inherit the called operation | Message-Operation Consistency |
 | Sequence message targets a method that exists only as a private inherited operation | Message-Operation Consistency |
diff --git a/validation/core/docs/specifications/component_public_api.md b/validation/core/docs/specifications/component_public_api.md
index 94006c9f..170b414b 100644
--- a/validation/core/docs/specifications/component_public_api.md
+++ b/validation/core/docs/specifications/component_public_api.md
@@ -40,9 +40,9 @@ Public API diagram entities must be declared as interfaces to be matched.
 Other entity types (e.g. a `class` with the same name) are not indexed as
 public API interfaces, so a same-named class does not satisfy the check.
 
-Matching is done by the public API diagram entity's **name** (not its fully
-qualified ID), compared case-sensitively against the static design interface's
-ID.
+Matching is done by the public API interface **id**, compared
+case-sensitively against the static design interface id. Display names remain
+diagnostic-only.
 
 ### Interface Declaration Consistency
 
@@ -50,9 +50,9 @@ Every public API interface declared in the static design diagram must resolve
 to an interface declared in the public API class diagram.
 *(Requirement: {requirement:downstream-ref}`Tools.ComponentPublicApiInterfaceDeclarationConsistency`)*
 
-The component public API interface is matched against public API interface
-entries derived from the public API diagram. Matching is exact and
-case-sensitive.
+The component public API interface is matched against public API interface ids
+derived from the public API diagram. Matching is exact and case-sensitive,
+with the existing normalization only bridging parser formatting differences.
 
 ```text
 ' static design diagram
diff --git a/validation/core/docs/specifications/component_sequence.md b/validation/core/docs/specifications/component_sequence.md
index f0ae9d1a..6d4d6575 100644
--- a/validation/core/docs/specifications/component_sequence.md
+++ b/validation/core/docs/specifications/component_sequence.md
@@ -20,24 +20,26 @@ This validator enforces consistency across entities in two diagram types:
 - **Component diagrams**
 - **Sequence diagrams**
 
-It shall make sure that Architectural Elements are consistently named and related to each other.
+It shall make sure that Architectural Elements are consistently identified and related to each other.
 
 ## What is Validated
 
 All comparisons are case-sensitive.
 
-### Alias Consistency
+### Unit/Participant Identifier Consistency
 
-Unit aliases from the component diagram must exactly match the set of
-participant aliases used across all sequence diagrams.
-*(Requirement: {requirement:downstream-ref}`Tools.ComponentSequenceAliasConsistency`)*
+Component-diagram unit ids must exactly match the set of participant uids used
+across all sequence diagrams.
+*(Requirement: {requirement:downstream-ref}`Tools.ComponentSequenceIdentifierConsistency`)*
 
-Component-diagram units without an explicit alias are ignored by this
-validator and are not required to appear as sequence participants. The
-special participant name `ExternalEndpoint` represents an external
-caller/callee outside the modeled units; it is exempt from Alias Consistency
-and may appear in sequence diagrams without a matching component-diagram
-unit.
+Units are validated by canonical id even when they have no explicit PlantUML
+alias. In sequence diagrams, participant `uid` is the canonical identifier
+used for matching. Sequence interaction sender/receiver names are resolved
+through the declared participant reference names back to those canonical uids.
+The special participant name `ExternalEndpoint` represents an external
+caller/callee outside the modeled units; it is exempt from identifier
+consistency and may appear in sequence diagrams without a matching
+component-diagram unit.
 
 ```text
 ' component diagram
@@ -93,8 +95,8 @@ component in the component diagram.
 
 | Failure case | Validation rule |
 |---|---|
-| Missing sequence participant | Alias Consistency |
-| Unexpected sequence participant | Alias Consistency |
+| Missing sequence participant | Unit/Participant Identifier Consistency |
+| Unexpected sequence participant | Unit/Participant Identifier Consistency |
 | Missing sequence interaction for interface-connected units | Interface-Connection Consistency |
 | Missing interface connection for sequence-connected units | Interface-Connection Consistency |
 
@@ -102,7 +104,7 @@ component in the component diagram.
 
 The validator emits debug output containing:
 
-- expected unit aliases
+- expected unit ids
 - observed participants
 - observed sequence calls (`caller -> callee : method`)
 - unit interface targets derived from the component diagram
diff --git a/validation/core/integration_test/class_design_implementation/BUILD b/validation/core/integration_test/class_design_implementation/BUILD
index fedf85a4..193af885 100644
--- a/validation/core/integration_test/class_design_implementation/BUILD
+++ b/validation/core/integration_test/class_design_implementation/BUILD
@@ -19,7 +19,6 @@ filegroup(
         "//validation/core/integration_test/class_design_implementation/negative_class_member_missing:case_data",
         "//validation/core/integration_test/class_design_implementation/negative_class_missing:case_data",
         "//validation/core/integration_test/class_design_implementation/negative_class_missing_with_suggestion:case_data",
-        "//validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion:case_data",
         "//validation/core/integration_test/class_design_implementation/negative_duplicate_class_entity_input:case_data",
         "//validation/core/integration_test/class_design_implementation/negative_entity_type_mismatch:case_data",
         "//validation/core/integration_test/class_design_implementation/negative_enum_literal_mismatch:case_data",
diff --git a/validation/core/integration_test/class_design_implementation/class_design_implementation_suite.rs b/validation/core/integration_test/class_design_implementation/class_design_implementation_suite.rs
index 18cbf7fb..80b17f3f 100644
--- a/validation/core/integration_test/class_design_implementation/class_design_implementation_suite.rs
+++ b/validation/core/integration_test/class_design_implementation/class_design_implementation_suite.rs
@@ -107,11 +107,6 @@ fn negative_class_missing_with_suggestion() {
     assert_case("negative_class_missing_with_suggestion");
 }
 
-#[test]
-fn negative_class_missing_without_suggestion() {
-    assert_case("negative_class_missing_without_suggestion");
-}
-
 #[test]
 fn negative_type_alias_missing_with_suggestion() {
     assert_case("negative_type_alias_missing_with_suggestion");
diff --git a/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/BUILD b/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/BUILD
deleted file mode 100644
index c3206a03..00000000
--- a/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/BUILD
+++ /dev/null
@@ -1,54 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "unit", "unit_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-unit_design(
-    name = "unit_design",
-    static = ["class_diagram.puml"],
-    visibility = ["//visibility:private"],
-)
-
-cc_library(
-    name = "transport",
-    srcs = ["transport.cpp"],
-)
-
-unit(
-    name = "unit",
-    testonly = False,
-    maturity = "development",
-    tests = [],
-    unit_design = [":unit_design"],
-    visibility = ["//visibility:private"],
-    implementation = [":transport"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:private"],
-    deps = [
-        ":unit",
-        ":unit_design",
-    ],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//validation/core/integration_test:__subpackages__"],
-)
diff --git a/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/transport.cpp b/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/transport.cpp
deleted file mode 100644
index e76a155f..00000000
--- a/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/transport.cpp
+++ /dev/null
@@ -1,24 +0,0 @@
-/********************************************************************************
- * Copyright (c) 2026 Contributors to the Eclipse Foundation
- *
- * See the NOTICE file(s) distributed with this work for additional
- * information regarding copyright ownership.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Apache License Version 2.0 which is available at
- * https://www.apache.org/licenses/LICENSE-2.0
- *
- * SPDX-License-Identifier: Apache-2.0
- ********************************************************************************/
-
-class Engine
-{
-};
-
-class Wheel
-{
-};
-
-class Dashboard
-{
-};
diff --git a/validation/core/integration_test/class_design_implementation/negative_type_alias_mismatch/expected.yaml b/validation/core/integration_test/class_design_implementation/negative_type_alias_mismatch/expected.yaml
index 385ece5a..e897efb7 100644
--- a/validation/core/integration_test/class_design_implementation/negative_type_alias_mismatch/expected.yaml
+++ b/validation/core/integration_test/class_design_implementation/negative_type_alias_mismatch/expected.yaml
@@ -15,10 +15,10 @@ error_contains: |
   [Implementation] Field type alias "Speed" original type on entity "Engine" differs between the unit design and the C++ class implementation.
     Entity                     : "Engine"
     Field                      : type alias "Speed" original type
-    Design value               : std::uint8_t
+    Design value               : uint8_t
     Design source file         : "validation/core/integration_test/class_design_implementation/negative_type_alias_mismatch/class_diagram.puml"
     Design source line         : 16
-    Implementation value       : std::uint16_t
+    Implementation value       : uint16_t
     Implementation source file : "validation/core/integration_test/class_design_implementation/negative_type_alias_mismatch/transport.cpp"
     Implementation source line : 16
     Fix                        : Make type alias "Speed" original type in entity "Engine" consistent between the unit design and the C++ class implementation.
diff --git a/validation/core/integration_test/class_design_sequence/BUILD b/validation/core/integration_test/class_design_sequence/BUILD
index 9ed70d42..0517b33b 100644
--- a/validation/core/integration_test/class_design_sequence/BUILD
+++ b/validation/core/integration_test/class_design_sequence/BUILD
@@ -16,21 +16,18 @@ load("@rules_rust//rust:defs.bzl", "rust_test")
 filegroup(
     name = "class_design_sequence_test_data",
     srcs = [
-        "//validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name:case_data",
+        "//validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class:case_data",
+        "//validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method:case_data",
         "//validation/core/integration_test/class_design_sequence/negative_participant_method_missing:case_data",
         "//validation/core/integration_test/class_design_sequence/negative_participant_method_missing_with_suggestion:case_data",
         "//validation/core/integration_test/class_design_sequence/negative_participant_missing:case_data",
         "//validation/core/integration_test/class_design_sequence/negative_participant_missing_with_suggestion:case_data",
-        "//validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method:case_data",
-        "//validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix:case_data",
-        "//validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons:case_data",
+        "//validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid:case_data",
+        "//validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch:case_data",
+        "//validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference:case_data",
         "//validation/core/integration_test/class_design_sequence/positive_participant_abstract_base_method_match:case_data",
-        "//validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match:case_data",
-        "//validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match:case_data",
         "//validation/core/integration_test/class_design_sequence/positive_participant_multilevel_inherited_method_match:case_data",
         "//validation/core/integration_test/class_design_sequence/positive_participant_namespace_callee_method_match:case_data",
-        "//validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match:case_data",
-        "//validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match:case_data",
         "//validation/core/integration_test/class_design_sequence/positive_participant_special_display_leading_colon_short_name_match:case_data",
         "//validation/core/integration_test/class_design_sequence/positive_participant_special_display_qualified_type_match:case_data",
         "//validation/core/integration_test/class_design_sequence/positive_participant_special_display_short_type_match:case_data",
diff --git a/validation/core/integration_test/class_design_sequence/class_design_sequence_suite.rs b/validation/core/integration_test/class_design_sequence/class_design_sequence_suite.rs
index 774cdcef..21b4436a 100644
--- a/validation/core/integration_test/class_design_sequence/class_design_sequence_suite.rs
+++ b/validation/core/integration_test/class_design_sequence/class_design_sequence_suite.rs
@@ -62,13 +62,18 @@ fn positive_participant_multilevel_inherited_method_match_suite_case() {
 }
 
 #[test]
-fn positive_participant_alias_display_name_class_name_match_suite_case() {
-    assert_case("positive_participant_alias_display_name_class_name_match");
+fn negative_participant_alias_display_name_not_matching_class_suite_case() {
+    assert_case("negative_participant_alias_display_name_not_matching_class");
 }
 
 #[test]
-fn positive_participant_alias_display_name_namespace_match_suite_case() {
-    assert_case("positive_participant_alias_display_name_namespace_match");
+fn negative_participant_reference_conflicting_uid_suite_case() {
+    assert_case("negative_participant_reference_conflicting_uid");
+}
+
+#[test]
+fn negative_participant_uid_duplicate_reference_suite_case() {
+    assert_case("negative_participant_uid_duplicate_reference");
 }
 
 #[test]
@@ -77,8 +82,8 @@ fn positive_participant_namespace_callee_method_match_suite_case() {
 }
 
 #[test]
-fn positive_participant_short_name_namespace_match_suite_case() {
-    assert_case("positive_participant_short_name_namespace_match");
+fn negative_participant_short_name_namespace_mismatch_suite_case() {
+    assert_case("negative_participant_short_name_namespace_mismatch");
 }
 
 #[test]
@@ -96,21 +101,11 @@ fn positive_participant_special_display_short_type_match_suite_case() {
     assert_case("positive_participant_special_display_short_type_match");
 }
 
-#[test]
-fn positive_participant_special_display_encoded_newline_match_suite_case() {
-    assert_case("positive_participant_special_display_encoded_newline_match");
-}
-
 #[test]
 fn negative_participant_missing_suite_case() {
     assert_case("negative_participant_missing");
 }
 
-#[test]
-fn negative_participant_ambiguous_short_name_suite_case() {
-    assert_case("negative_participant_ambiguous_short_name");
-}
-
 #[test]
 fn negative_participant_method_missing_suite_case() {
     assert_case("negative_participant_method_missing");
@@ -122,21 +117,11 @@ fn negative_participant_method_missing_with_suggestion_suite_case() {
 }
 
 #[test]
-fn negative_participant_private_inherited_method_suite_case() {
-    assert_case("negative_participant_private_inherited_method");
+fn negative_participant_inaccessible_inherited_method_suite_case() {
+    assert_case("negative_participant_inaccessible_inherited_method");
 }
 
 #[test]
 fn negative_participant_missing_with_suggestion_suite_case() {
     assert_case("negative_participant_missing_with_suggestion");
 }
-
-#[test]
-fn negative_participant_special_display_multiple_colons_suite_case() {
-    assert_case("negative_participant_special_display_multiple_colons");
-}
-
-#[test]
-fn negative_participant_special_display_empty_suffix_suite_case() {
-    assert_case("negative_participant_special_display_empty_suffix");
-}
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/BUILD b/validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/BUILD
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/BUILD
rename to validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/BUILD
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/class_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/class_diagram.puml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/class_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/class_diagram.puml
diff --git a/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/expected.yaml b/validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/expected.yaml
similarity index 50%
rename from validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/expected.yaml
rename to validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/expected.yaml
index 751b2430..c9e3eb59 100644
--- a/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/expected.yaml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/expected.yaml
@@ -11,9 +11,10 @@
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
 should_pass: false
-error_contains: |-
-  [Class] Class "TelemetryBroker" from the unit design not found in the C++ class implementation.
-    Class              : "TelemetryBroker"
-    Design source file : "validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/class_diagram.puml"
-    Design source line : 16
-    Fix                : Add implementation class "TelemetryBroker" in the C++ class implementation, or remove it from the unit design.
+error_contains: |
+  [Class] Sequence participant "Repository" has no matching class in the class diagram.
+    Participant                 : "Repository"
+    Sequence source file        : "validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/sequence_diagram.puml"
+    Sequence source line        : 16
+    Suggestion for "Repository" : Did you mean class "A.Repository"?
+    Fix                         : Add class "A.Repository" to the class diagram, or remove the participant from the sequence diagram.
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/sequence_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/sequence_diagram.puml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/sequence_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_alias_display_name_not_matching_class/sequence_diagram.puml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/BUILD b/validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/BUILD
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/BUILD
rename to validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/BUILD
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/class_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/class_diagram.puml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/class_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/class_diagram.puml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/expected.yaml b/validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/expected.yaml
similarity index 92%
rename from validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/expected.yaml
rename to validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/expected.yaml
index f7861b4a..bdd769c2 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/expected.yaml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/expected.yaml
@@ -15,6 +15,6 @@ error_contains: |
   [Method] Sequence function "LoadState" from sequence call "StateStore" -> "StateStore" : "LoadState" exists only as a private inherited method on target class "StateStore" in the class diagram.
     Sequence call        : "StateStore" -> "StateStore" : "LoadState"
     Target class         : "StateStore"
-    Sequence source file : "validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/sequence_diagram.puml"
+    Sequence source file : "validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/sequence_diagram.puml"
     Sequence source line : 18
     Fix                  : Consider changing method "LoadState" to public or protected on an inherited type of class "StateStore", add an accessible wrapper on that class, or change or remove that sequence call.
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/sequence_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/sequence_diagram.puml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/negative_participant_private_inherited_method/sequence_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_inaccessible_inherited_method/sequence_diagram.puml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_missing/expected.yaml b/validation/core/integration_test/class_design_sequence/negative_participant_missing/expected.yaml
index 1a111261..af295a5c 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_missing/expected.yaml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_missing/expected.yaml
@@ -13,7 +13,8 @@
 should_pass: false
 error_contains: |
   [Class] Sequence participant "Repository" has no matching class in the class diagram.
-    Participant          : "Repository"
-    Sequence source file : "validation/core/integration_test/class_design_sequence/negative_participant_missing/sequence_diagram.puml"
-    Sequence source line : 16
-    Fix                  : Add class "Repository" to the class diagram, or remove the participant from the sequence diagram.
+    Participant                 : "Repository"
+    Sequence source file        : "validation/core/integration_test/class_design_sequence/negative_participant_missing/sequence_diagram.puml"
+    Sequence source line        : 16
+    Suggestion for "Repository" : Did you mean class "Controller"?
+    Fix                         : Add class "Repository" to the class diagram, or remove the participant from the sequence diagram.
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/BUILD b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/BUILD
similarity index 93%
rename from validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/BUILD
rename to validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/BUILD
index 30f3d121..9258c7c9 100644
--- a/validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/BUILD
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/BUILD
@@ -16,7 +16,10 @@ load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixtur
 
 unit_design(
     name = "unit_design",
-    dynamic = ["sequence_diagram.puml"],
+    dynamic = [
+        "sequence_a.puml",
+        "sequence_b.puml",
+    ],
     static = ["class_diagram.puml"],
     visibility = ["//visibility:private"],
 )
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/class_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/class_diagram.puml
similarity index 90%
rename from validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/class_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/class_diagram.puml
index c7846db4..268161d4 100644
--- a/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/class_diagram.puml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/class_diagram.puml
@@ -13,8 +13,10 @@
 
 @startuml class_diagram
 
-class Process {
-	+ Execute() : void
+namespace A {
+    class Service {
+        + Handle() : void
+    }
 }
 
 @enduml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/expected.yaml b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/expected.yaml
new file mode 100644
index 00000000..238e7102
--- /dev/null
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/expected.yaml
@@ -0,0 +1,23 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+should_pass: false
+error_contains: |
+  [Design] Sequence participant uid "validation.core.integration_test.class_design_sequence.negative_participant_reference_conflicting_uid.A.Service" is declared with conflicting reference names.
+    Participant uid                      : "validation.core.integration_test.class_design_sequence.negative_participant_reference_conflicting_uid.A.Service"
+    First participant reference name     : "ServiceA"
+    Duplicate participant reference name : "ServiceB"
+    First sequence source file           : "validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/sequence_a.puml"
+    First sequence source line           : 16
+    Duplicate sequence source file       : "validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/sequence_b.puml"
+    Duplicate sequence source line       : 16
+    Fix                                  : Use one reference name consistently for the same sequence participant uid.
diff --git a/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/class_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/sequence_a.puml
similarity index 86%
rename from validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/class_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/sequence_a.puml
index c6c7f7a9..1ef883e3 100644
--- a/validation/core/integration_test/class_design_implementation/negative_class_missing_without_suggestion/class_diagram.puml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/sequence_a.puml
@@ -11,8 +11,10 @@
 ' SPDX-License-Identifier: Apache-2.0
 ' *******************************************************************************
 
-@startuml
+@startuml sequence_a
 
-class TelemetryBroker
+participant "A::Service" as ServiceA
+
+ServiceA -> ServiceA : Handle()
 
 @enduml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/class_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/sequence_b.puml
similarity index 86%
rename from validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/class_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/sequence_b.puml
index be9fcad7..bddeb0ca 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/class_diagram.puml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_reference_conflicting_uid/sequence_b.puml
@@ -11,8 +11,10 @@
 ' SPDX-License-Identifier: Apache-2.0
 ' *******************************************************************************
 
-@startuml class_diagram
+@startuml sequence_b
 
-class Runtime
+participant "A::Service" as ServiceB
+
+ServiceB -> ServiceB : Handle()
 
 @enduml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/BUILD b/validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/BUILD
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/BUILD
rename to validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/BUILD
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/class_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/class_diagram.puml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/class_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/class_diagram.puml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/expected.yaml b/validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/expected.yaml
similarity index 52%
rename from validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/expected.yaml
rename to validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/expected.yaml
index ae97a157..a948fa3d 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/expected.yaml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/expected.yaml
@@ -12,9 +12,9 @@
 # *******************************************************************************
 should_pass: false
 error_contains: |
-  [Class] Sequence participant "Controller" matches multiple classes in the class diagram.
-    Participant          : "Controller"
-    Matching classes     : "unit_1.Controller", "unit_2.Controller"
-    Sequence source file : "validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/sequence_diagram.puml"
-    Sequence source line : 16
-    Fix                  : Rename participant "Controller" in the sequence diagram to a unique class id, or rename one of the matching classes in the class diagram.
+  [Class] Sequence participant "Repository" has no matching class in the class diagram.
+    Participant                 : "Repository"
+    Sequence source file        : "validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/sequence_diagram.puml"
+    Sequence source line        : 16
+    Suggestion for "Repository" : Did you mean class "A.Repository"?
+    Fix                         : Add class "A.Repository" to the class diagram, or remove the participant from the sequence diagram.
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/sequence_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/sequence_diagram.puml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/sequence_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_short_name_namespace_mismatch/sequence_diagram.puml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/expected.yaml b/validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/expected.yaml
deleted file mode 100644
index 9185e237..00000000
--- a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/expected.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains: |-
-  [Class] Sequence participant "singletonInstance:" uses an invalid kind of display name.
-    Participant          : "singletonInstance:"
-    Display name         : "singletonInstance:"
-    Invalid form         : "singletonInstance:" uses ':' without a non-empty right-hand side
-    Sequence source file : "validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/sequence_diagram.puml"
-    Sequence source line : 16
-    Fix                  : Use one supported form such as :Name, prefix:qualified::Type, or provide an unambiguous alias.
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/class_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/class_diagram.puml
deleted file mode 100644
index 92441dc6..00000000
--- a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/class_diagram.puml
+++ /dev/null
@@ -1,26 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml class_diagram
-
-namespace score {
-	namespace mw {
-		namespace com {
-			namespace impl {
-				class Runtime
-			}
-		}
-	}
-}
-
-@enduml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/expected.yaml b/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/expected.yaml
deleted file mode 100644
index a481fcfb..00000000
--- a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/expected.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains: |
-  [Class] Sequence participant "instance:score::mw::com::impl::Runtime:Impl" uses an invalid kind of display name.
-    Participant          : "instance:score::mw::com::impl::Runtime:Impl"
-    Display name         : "instance:score::mw::com::impl::Runtime:Impl"
-    Invalid form         : "instance:score::mw::com::impl::Runtime:Impl" contains multiple standalone ':' separators
-    Sequence source file : "validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/sequence_diagram.puml"
-    Sequence source line : 16
-    Fix                  : Use one supported form such as :Name, prefix:qualified::Type, or provide an unambiguous alias.
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/BUILD b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/BUILD
similarity index 93%
rename from validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/BUILD
rename to validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/BUILD
index 30f3d121..9258c7c9 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/BUILD
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/BUILD
@@ -16,7 +16,10 @@ load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixtur
 
 unit_design(
     name = "unit_design",
-    dynamic = ["sequence_diagram.puml"],
+    dynamic = [
+        "sequence_a.puml",
+        "sequence_b.puml",
+    ],
     static = ["class_diagram.puml"],
     visibility = ["//visibility:private"],
 )
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/class_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/class_diagram.puml
similarity index 82%
rename from validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/class_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/class_diagram.puml
index 9725a38f..5395665a 100644
--- a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/class_diagram.puml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/class_diagram.puml
@@ -13,9 +13,15 @@
 
 @startuml class_diagram
 
-namespace unit_1 {
-    class Controller {
-        + Execute() : void
+namespace A {
+    class Service {
+        + Handle() : void
+    }
+}
+
+namespace B {
+    class Service {
+        + Handle() : void
     }
 }
 
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/expected.yaml b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/expected.yaml
new file mode 100644
index 00000000..c75e2a59
--- /dev/null
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/expected.yaml
@@ -0,0 +1,23 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+should_pass: false
+error_contains: |
+  [Design] Sequence participant reference name "Service" refers to multiple uids.
+    Participant reference name     : "Service"
+    First participant uid          : "A.Service"
+    Duplicate participant uid      : "B.Service"
+    First sequence source file     : "validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/sequence_a.puml"
+    First sequence source line     : 16
+    Duplicate sequence source file : "validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/sequence_b.puml"
+    Duplicate sequence source line : 16
+    Fix                            : Rename one participant alias or use a unique participant reference name.
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/sequence_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/sequence_a.puml
similarity index 86%
rename from validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/sequence_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/sequence_a.puml
index 327c0a62..433907b4 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_ambiguous_short_name/sequence_diagram.puml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/sequence_a.puml
@@ -11,10 +11,10 @@
 ' SPDX-License-Identifier: Apache-2.0
 ' *******************************************************************************
 
-@startuml sequence_diagram
+@startuml sequence_a
 
-participant Controller
+participant "A::Service" as Service
 
-Controller -> Controller : Execute()
+Service -> Service : Handle()
 
 @enduml
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/sequence_diagram.puml b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/sequence_b.puml
similarity index 86%
rename from validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/sequence_diagram.puml
rename to validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/sequence_b.puml
index 6b00f453..b6dbc81b 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_empty_suffix/sequence_diagram.puml
+++ b/validation/core/integration_test/class_design_sequence/negative_participant_uid_duplicate_reference/sequence_b.puml
@@ -11,8 +11,10 @@
 ' SPDX-License-Identifier: Apache-2.0
 ' *******************************************************************************
 
-@startuml sequence_diagram
+@startuml sequence_b
 
-participant "singletonInstance:"
+participant "B::Service" as Service
+
+Service -> Service : Handle()
 
 @enduml
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/BUILD b/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/BUILD
deleted file mode 100644
index 30f3d121..00000000
--- a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/BUILD
+++ /dev/null
@@ -1,37 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "unit_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-unit_design(
-    name = "unit_design",
-    dynamic = ["sequence_diagram.puml"],
-    static = ["class_diagram.puml"],
-    visibility = ["//visibility:private"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:private"],
-    deps = [":unit_design"],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//validation/core/integration_test:__subpackages__"],
-)
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/BUILD b/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/BUILD
deleted file mode 100644
index 30f3d121..00000000
--- a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/BUILD
+++ /dev/null
@@ -1,37 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "unit_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-unit_design(
-    name = "unit_design",
-    dynamic = ["sequence_diagram.puml"],
-    static = ["class_diagram.puml"],
-    visibility = ["//visibility:private"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:private"],
-    deps = [":unit_design"],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//validation/core/integration_test:__subpackages__"],
-)
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/BUILD b/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/BUILD
deleted file mode 100644
index 30f3d121..00000000
--- a/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/BUILD
+++ /dev/null
@@ -1,37 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "unit_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-unit_design(
-    name = "unit_design",
-    dynamic = ["sequence_diagram.puml"],
-    static = ["class_diagram.puml"],
-    visibility = ["//visibility:private"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:private"],
-    deps = [":unit_design"],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//validation/core/integration_test:__subpackages__"],
-)
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/sequence_diagram.puml b/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/sequence_diagram.puml
deleted file mode 100644
index d0d83fe1..00000000
--- a/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/sequence_diagram.puml
+++ /dev/null
@@ -1,20 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml sequence_diagram
-
-participant ":Process/nara::com user" as help
-
-help -> help : Execute()
-
-@enduml
diff --git a/validation/core/integration_test/component_internal_api/BUILD b/validation/core/integration_test/component_internal_api/BUILD
index 7b4e9588..b17742ca 100644
--- a/validation/core/integration_test/component_internal_api/BUILD
+++ b/validation/core/integration_test/component_internal_api/BUILD
@@ -16,10 +16,9 @@ load("@rules_rust//rust:defs.bzl", "rust_test")
 filegroup(
     name = "component_internal_api_test_data",
     srcs = [
-        "//validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api:case_data",
-        "//validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion:case_data",
-        "//validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions:case_data",
-        "//validation/core/integration_test/component_internal_api/positive_interface_match:case_data",
+        "//validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api:case_data",
+        "//validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions:case_data",
+        "//validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api:case_data",
     ],
 )
 
diff --git a/validation/core/integration_test/component_internal_api/component_internal_api_suite.rs b/validation/core/integration_test/component_internal_api/component_internal_api_suite.rs
index bc3db758..a2a3e538 100644
--- a/validation/core/integration_test/component_internal_api/component_internal_api_suite.rs
+++ b/validation/core/integration_test/component_internal_api/component_internal_api_suite.rs
@@ -52,21 +52,16 @@ fn assert_case(case_dir: &str) {
 }
 
 #[test]
-fn negative_interface_missing_from_internal_api_suite_case() {
-    assert_case("negative_interface_missing_from_internal_api");
+fn negative_component_interface_missing_from_internal_api_suite_case() {
+    assert_case("negative_component_interface_missing_from_internal_api");
 }
 
 #[test]
-fn negative_interface_missing_from_internal_api_with_suggestion_suite_case() {
-    assert_case("negative_interface_missing_from_internal_api_with_suggestion");
+fn negative_component_interfaces_missing_from_internal_api_with_suggestions_suite_case() {
+    assert_case("negative_component_interfaces_missing_from_internal_api_with_suggestions");
 }
 
 #[test]
-fn negative_interfaces_missing_from_internal_api_with_suggestions_suite_case() {
-    assert_case("negative_interfaces_missing_from_internal_api_with_suggestions");
-}
-
-#[test]
-fn positive_interface_match_suite_case() {
-    assert_case("positive_interface_match");
+fn positive_component_interfaces_match_internal_api_suite_case() {
+    assert_case("positive_component_interfaces_match_internal_api");
 }
diff --git a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/BUILD b/validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/BUILD
similarity index 100%
rename from validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/BUILD
rename to validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/BUILD
diff --git a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/component_diagram.puml b/validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/component_diagram.puml
rename to validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/component_diagram.puml
diff --git a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/expected.yaml b/validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/expected.yaml
similarity index 94%
rename from validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/expected.yaml
rename to validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/expected.yaml
index bc85250e..a57f54ba 100644
--- a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/expected.yaml
+++ b/validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/expected.yaml
@@ -14,6 +14,6 @@ should_pass: false
 error_contains: |
   [Interface] Component interface(s) "package_a.InternalInterface" from the component diagram not found in the internal API diagram.
     Missing interfaces                                      : "package_a.InternalInterface"
-    Component source file for "package_a.InternalInterface" : "validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/component_diagram.puml"
+    Component source file for "package_a.InternalInterface" : "validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/component_diagram.puml"
     Component source line for "package_a.InternalInterface" : 22
     Fix                                                     : Add interface declaration(s) "package_a.InternalInterface" in the internal API diagram, or remove those interface declarations from the component diagram.
diff --git a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/internal_api_diagram.puml b/validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/internal_api_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api/internal_api_diagram.puml
rename to validation/core/integration_test/component_internal_api/negative_component_interface_missing_from_internal_api/internal_api_diagram.puml
diff --git a/validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/BUILD b/validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/BUILD
similarity index 100%
rename from validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/BUILD
rename to validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/BUILD
diff --git a/validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/component_diagram.puml b/validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/component_diagram.puml
rename to validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/component_diagram.puml
diff --git a/validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/expected.yaml b/validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/expected.yaml
similarity index 85%
rename from validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/expected.yaml
rename to validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/expected.yaml
index 03bca386..e8b43fb5 100644
--- a/validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/expected.yaml
+++ b/validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/expected.yaml
@@ -14,10 +14,10 @@ should_pass: false
 error_contains: |-
   [Interface] Component interface(s) "package_a.DiagnosticsInterface", "package_a.InternalInterface" from the component diagram not found in the internal API diagram.
     Missing interfaces                                         : "package_a.DiagnosticsInterface", "package_a.InternalInterface"
-    Component source file for "package_a.DiagnosticsInterface" : "validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/component_diagram.puml"
+    Component source file for "package_a.DiagnosticsInterface" : "validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/component_diagram.puml"
     Component source line for "package_a.DiagnosticsInterface" : 22
-    Suggestion for "package_a.DiagnosticsInterface"            : Did you mean interface "package_a.diagnostics_interfac"?
-    Component source file for "package_a.InternalInterface"    : "validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/component_diagram.puml"
+    Suggestion for "package_a.DiagnosticsInterface"            : Did you mean interface "package_a_DiagnosticsInterfac"?
+    Component source file for "package_a.InternalInterface"    : "validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/component_diagram.puml"
     Component source line for "package_a.InternalInterface"    : 23
-    Suggestion for "package_a.InternalInterface"               : Did you mean interface "package_a.internal_interface"?
+    Suggestion for "package_a.InternalInterface"               : Did you mean interface "package_a_InternalInterfac"?
     Fix                                                        : Add interface declaration(s) "package_a.DiagnosticsInterface", "package_a.InternalInterface" in the internal API diagram, or remove those interface declarations from the component diagram.
diff --git a/validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/internal_api_diagram.puml b/validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/internal_api_diagram.puml
similarity index 81%
rename from validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/internal_api_diagram.puml
rename to validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/internal_api_diagram.puml
index 9ea9ab86..0f5e9723 100644
--- a/validation/core/integration_test/component_internal_api/negative_interfaces_missing_from_internal_api_with_suggestions/internal_api_diagram.puml
+++ b/validation/core/integration_test/component_internal_api/negative_component_interfaces_missing_from_internal_api_with_suggestions/internal_api_diagram.puml
@@ -14,11 +14,11 @@
 @startuml
 
 package package_a {
-    interface "diagnostics_interfac" as diagnostics_interfac {
+    interface "package_a.DiagnosticsInterfac" as package_a_DiagnosticsInterfac {
         + GetDiagnostics()
     }
 
-    interface "internal_interface" as internal_interface {
+    interface "package_a.InternalInterfac" as package_a_InternalInterfac {
         + GetData()
     }
 }
diff --git a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/BUILD b/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/BUILD
deleted file mode 100644
index 26b6054f..00000000
--- a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/BUILD
+++ /dev/null
@@ -1,38 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "architectural_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-architectural_design(
-    name = "design",
-    internal_api = ["internal_api_diagram.puml"],
-    maturity = "development",
-    static = ["component_diagram.puml"],
-    visibility = ["//visibility:private"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:public"],
-    deps = [":design"],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//visibility:public"],
-)
diff --git a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/expected.yaml b/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/expected.yaml
deleted file mode 100644
index a95bf27e..00000000
--- a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/expected.yaml
+++ /dev/null
@@ -1,20 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains: |-
-  [Interface] Component interface(s) "package_a.InternalInterface" from the component diagram not found in the internal API diagram.
-    Missing interfaces                                      : "package_a.InternalInterface"
-    Component source file for "package_a.InternalInterface" : "validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/component_diagram.puml"
-    Component source line for "package_a.InternalInterface" : 22
-    Suggestion for "package_a.InternalInterface"            : Did you mean interface "package_a.internal_interface"?
-    Fix                                                     : Add interface declaration(s) "package_a.InternalInterface" in the internal API diagram, or remove those interface declarations from the component diagram.
diff --git a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/internal_api_diagram.puml b/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/internal_api_diagram.puml
deleted file mode 100644
index 5a9f457d..00000000
--- a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/internal_api_diagram.puml
+++ /dev/null
@@ -1,22 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml
-
-package package_a {
-    interface "internal_interface" as internal_interface {
-        + GetData()
-    }
-}
-
-@enduml
diff --git a/validation/core/integration_test/component_internal_api/positive_interface_match/BUILD b/validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api/BUILD
similarity index 100%
rename from validation/core/integration_test/component_internal_api/positive_interface_match/BUILD
rename to validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api/BUILD
diff --git a/validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/component_diagram.puml b/validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_internal_api/negative_interface_missing_from_internal_api_with_suggestion/component_diagram.puml
rename to validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api/component_diagram.puml
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/expected.yaml b/validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api/expected.yaml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_class_name_match/expected.yaml
rename to validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api/expected.yaml
diff --git a/validation/core/integration_test/component_internal_api/positive_interface_match/internal_api_diagram.puml b/validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api/internal_api_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_internal_api/positive_interface_match/internal_api_diagram.puml
rename to validation/core/integration_test/component_internal_api/positive_component_interfaces_match_internal_api/internal_api_diagram.puml
diff --git a/validation/core/integration_test/component_public_api/BUILD b/validation/core/integration_test/component_public_api/BUILD
index 084936a5..16450c1b 100644
--- a/validation/core/integration_test/component_public_api/BUILD
+++ b/validation/core/integration_test/component_public_api/BUILD
@@ -16,14 +16,13 @@ load("@rules_rust//rust:defs.bzl", "rust_test")
 filegroup(
     name = "component_public_api_test_data",
     srcs = [
-        "//validation/core/integration_test/component_public_api/negative_case_sensitive:case_data",
-        "//validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship:case_data",
-        "//validation/core/integration_test/component_public_api/negative_public_api_missing:case_data",
-        "//validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion:case_data",
-        "//validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions:case_data",
-        "//validation/core/integration_test/component_public_api/negative_public_api_wrong_type:case_data",
+        "//validation/core/integration_test/component_public_api/negative_public_api_case_mismatch:case_data",
+        "//validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing:case_data",
+        "//validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship:case_data",
+        "//validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram:case_data",
+        "//validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions:case_data",
         "//validation/core/integration_test/component_public_api/positive_overview_seooc_relation_merge:case_data",
-        "//validation/core/integration_test/component_public_api/positive_public_api_match:case_data",
+        "//validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc:case_data",
     ],
 )
 
diff --git a/validation/core/integration_test/component_public_api/component_public_api_suite.rs b/validation/core/integration_test/component_public_api/component_public_api_suite.rs
index 9f78c924..71a140ef 100644
--- a/validation/core/integration_test/component_public_api/component_public_api_suite.rs
+++ b/validation/core/integration_test/component_public_api/component_public_api_suite.rs
@@ -50,8 +50,8 @@ fn assert_case(case_dir: &str) {
 }
 
 #[test]
-fn positive_public_api_match_suite_case() {
-    assert_case("positive_public_api_match");
+fn positive_public_api_declared_and_related_to_seooc_suite_case() {
+    assert_case("positive_public_api_declared_and_related_to_seooc");
 }
 
 #[test]
@@ -60,31 +60,26 @@ fn positive_overview_seooc_relation_merge_suite_case() {
 }
 
 #[test]
-fn negative_public_api_missing_suite_case() {
-    assert_case("negative_public_api_missing");
+fn negative_public_apis_missing_from_public_api_diagram_suite_case() {
+    assert_case("negative_public_apis_missing_from_public_api_diagram");
 }
 
 #[test]
-fn negative_public_api_missing_with_suggestion_suite_case() {
-    assert_case("negative_public_api_missing_with_suggestion");
+fn negative_public_apis_missing_from_public_api_diagram_with_suggestions_suite_case() {
+    assert_case("negative_public_apis_missing_from_public_api_diagram_with_suggestions");
 }
 
 #[test]
-fn negative_public_api_missing_with_suggestions_suite_case() {
-    assert_case("negative_public_api_missing_with_suggestions");
+fn negative_public_api_declared_as_class_is_treated_as_missing_suite_case() {
+    assert_case("negative_public_api_declared_as_class_is_treated_as_missing");
 }
 
 #[test]
-fn negative_public_api_wrong_type_suite_case() {
-    assert_case("negative_public_api_wrong_type");
+fn negative_public_api_case_mismatch_suite_case() {
+    assert_case("negative_public_api_case_mismatch");
 }
 
 #[test]
-fn negative_case_sensitive_suite_case() {
-    assert_case("negative_case_sensitive");
-}
-
-#[test]
-fn negative_public_api_lack_of_relationship_suite_case() {
-    assert_case("negative_public_api_lack_of_relationship");
+fn negative_public_api_without_seooc_relationship_suite_case() {
+    assert_case("negative_public_api_without_seooc_relationship");
 }
diff --git a/validation/core/integration_test/component_public_api/negative_case_sensitive/BUILD b/validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/BUILD
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_case_sensitive/BUILD
rename to validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/BUILD
diff --git a/validation/core/integration_test/component_public_api/negative_case_sensitive/expected.yaml b/validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/expected.yaml
similarity index 92%
rename from validation/core/integration_test/component_public_api/negative_case_sensitive/expected.yaml
rename to validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/expected.yaml
index 3237997c..0426490b 100644
--- a/validation/core/integration_test/component_public_api/negative_case_sensitive/expected.yaml
+++ b/validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/expected.yaml
@@ -14,6 +14,6 @@ should_pass: false
 error_contains: |
   [Interface] Public API interface(s) "SampleLibraryAPI" from the static diagram not found in the public API diagram; use "SampleLibraryAPI" (case-sensitive).
     Missing public APIs                       : "SampleLibraryAPI"
-    Static source file for "SampleLibraryAPI" : "validation/core/integration_test/component_public_api/negative_case_sensitive/static_design.puml"
+    Static source file for "SampleLibraryAPI" : "validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/static_design.puml"
     Static source line for "SampleLibraryAPI" : 24
     Fix                                       : Add public API declaration(s) "SampleLibraryAPI" in the public API diagram, or remove those interface declarations from the static diagram; if already declared, use "SampleLibraryAPI" (case-sensitive).
diff --git a/validation/core/integration_test/component_public_api/negative_case_sensitive/public_api.puml b/validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/public_api.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_case_sensitive/public_api.puml
rename to validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/public_api.puml
diff --git a/validation/core/integration_test/component_public_api/negative_case_sensitive/static_design.puml b/validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/static_design.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_case_sensitive/static_design.puml
rename to validation/core/integration_test/component_public_api/negative_public_api_case_mismatch/static_design.puml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/BUILD b/validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/BUILD
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/BUILD
rename to validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/BUILD
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_wrong_type/expected.yaml b/validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/expected.yaml
similarity index 90%
rename from validation/core/integration_test/component_public_api/negative_public_api_wrong_type/expected.yaml
rename to validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/expected.yaml
index cf62042a..d6065f48 100644
--- a/validation/core/integration_test/component_public_api/negative_public_api_wrong_type/expected.yaml
+++ b/validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/expected.yaml
@@ -14,6 +14,6 @@ should_pass: false
 error_contains: |
   [Interface] Public API interface(s) "SampleLibraryAPI" from the static diagram not found in the public API diagram.
     Missing public APIs                       : "SampleLibraryAPI"
-    Static source file for "SampleLibraryAPI" : "validation/core/integration_test/component_public_api/negative_public_api_wrong_type/static_design.puml"
+    Static source file for "SampleLibraryAPI" : "validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/static_design.puml"
     Static source line for "SampleLibraryAPI" : 22
     Fix                                       : Add public API declaration(s) "SampleLibraryAPI" in the public API diagram, or remove those interface declarations from the static diagram.
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_wrong_type/public_api.puml b/validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/public_api.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_wrong_type/public_api.puml
rename to validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/public_api.puml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_wrong_type/static_design.puml b/validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/static_design.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_wrong_type/static_design.puml
rename to validation/core/integration_test/component_public_api/negative_public_api_declared_as_class_is_treated_as_missing/static_design.puml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/expected.yaml b/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/expected.yaml
deleted file mode 100644
index 730be9e6..00000000
--- a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/expected.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains:
-  - |-
-    [Interface] Public API interface(s) "SampleLibraryAPI" from the static diagram not found in the public API diagram.
-      Missing public APIs                       : "SampleLibraryAPI"
-      Static source file for "SampleLibraryAPI" : "validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/static_design.puml"
-      Static source line for "SampleLibraryAPI" : 20
-      Suggestion for "SampleLibraryAPI"         : Did you mean interface "SampleLibraryAP"?
-      Fix                                       : Add public API declaration(s) "SampleLibraryAPI" in the public API diagram, or remove those interface declarations from the static diagram.
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/public_api.puml b/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/public_api.puml
deleted file mode 100644
index 3be39902..00000000
--- a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/public_api.puml
+++ /dev/null
@@ -1,20 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml public_api
-
-interface "Sample Library AP" as SampleLibraryAP <<interface>> {
-    +GetNumber(): int
-}
-
-@enduml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/static_design.puml b/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/static_design.puml
deleted file mode 100644
index 0e2d1f30..00000000
--- a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/static_design.puml
+++ /dev/null
@@ -1,24 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml static_design
-
-package "Sample Seooc" as sample_seooc <<SEooC>> {
-    portout sample_seooc_public_api_port
-}
-
-interface "SampleLibraryAPI" as SampleLibraryAPI
-
-sample_seooc_public_api_port )-d- SampleLibraryAPI
-
-@enduml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing/BUILD b/validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/BUILD
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing/BUILD
rename to validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/BUILD
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/expected.yaml b/validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/expected.yaml
similarity index 91%
rename from validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/expected.yaml
rename to validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/expected.yaml
index 3b89406f..fde8460c 100644
--- a/validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/expected.yaml
+++ b/validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/expected.yaml
@@ -14,6 +14,6 @@ should_pass: false
 error_contains: |
   [Interface] Public API interface(s) "SampleLibraryAPI" in the static diagram have no relationship to the SEooC.
     Public APIs                               : "SampleLibraryAPI"
-    Static source file for "SampleLibraryAPI" : "validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/static_design.puml"
+    Static source file for "SampleLibraryAPI" : "validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/static_design.puml"
     Static source line for "SampleLibraryAPI" : 22
     Fix                                       : Connect public API interface(s) "SampleLibraryAPI" from the SEooC boundary in the static diagram, or remove those interface declarations if they are not intended to be public.
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/public_api.puml b/validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/public_api.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/public_api.puml
rename to validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/public_api.puml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/static_design.puml b/validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/static_design.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_lack_of_relationship/static_design.puml
rename to validation/core/integration_test/component_public_api/negative_public_api_without_seooc_relationship/static_design.puml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_wrong_type/BUILD b/validation/core/integration_test/component_public_api/negative_public_api_wrong_type/BUILD
deleted file mode 100644
index 071e5aec..00000000
--- a/validation/core/integration_test/component_public_api/negative_public_api_wrong_type/BUILD
+++ /dev/null
@@ -1,38 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "architectural_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-architectural_design(
-    name = "design",
-    maturity = "development",
-    public_api = ["public_api.puml"],
-    static = ["static_design.puml"],
-    visibility = ["//visibility:private"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:private"],
-    deps = [":design"],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//validation/core/integration_test:__subpackages__"],
-)
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/BUILD b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/BUILD
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestion/BUILD
rename to validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/BUILD
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing/expected.yaml b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/expected.yaml
similarity index 84%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing/expected.yaml
rename to validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/expected.yaml
index bfa2882c..559e3103 100644
--- a/validation/core/integration_test/component_public_api/negative_public_api_missing/expected.yaml
+++ b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/expected.yaml
@@ -14,8 +14,8 @@ should_pass: false
 error_contains: |
   [Interface] Public API interface(s) "SampleLibraryAPI1", "SampleLibraryAPI2" from the static diagram not found in the public API diagram.
     Missing public APIs                        : "SampleLibraryAPI1", "SampleLibraryAPI2"
-    Static source file for "SampleLibraryAPI1" : "validation/core/integration_test/component_public_api/negative_public_api_missing/static_design.puml"
+    Static source file for "SampleLibraryAPI1" : "validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/static_design.puml"
     Static source line for "SampleLibraryAPI1" : 24
-    Static source file for "SampleLibraryAPI2" : "validation/core/integration_test/component_public_api/negative_public_api_missing/static_design.puml"
+    Static source file for "SampleLibraryAPI2" : "validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/static_design.puml"
     Static source line for "SampleLibraryAPI2" : 25
     Fix                                        : Add public API declaration(s) "SampleLibraryAPI1", "SampleLibraryAPI2" in the public API diagram, or remove those interface declarations from the static diagram.
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing/public_api.puml b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/public_api.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing/public_api.puml
rename to validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/public_api.puml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing/static_design.puml b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/static_design.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing/static_design.puml
rename to validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram/static_design.puml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/BUILD b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/BUILD
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/BUILD
rename to validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/BUILD
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/expected.yaml b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/expected.yaml
similarity index 84%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/expected.yaml
rename to validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/expected.yaml
index b74308eb..1e508b51 100644
--- a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/expected.yaml
+++ b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/expected.yaml
@@ -14,10 +14,10 @@ should_pass: false
 error_contains: |-
   [Interface] Public API interface(s) "SampleLibraryAPI1", "SampleLibraryAPI2" from the static diagram not found in the public API diagram.
     Missing public APIs                        : "SampleLibraryAPI1", "SampleLibraryAPI2"
-    Static source file for "SampleLibraryAPI1" : "validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/static_design.puml"
+    Static source file for "SampleLibraryAPI1" : "validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/static_design.puml"
     Static source line for "SampleLibraryAPI1" : 20
     Suggestion for "SampleLibraryAPI1"         : Did you mean interface "SampleLibraryAP1"?
-    Static source file for "SampleLibraryAPI2" : "validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/static_design.puml"
+    Static source file for "SampleLibraryAPI2" : "validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/static_design.puml"
     Static source line for "SampleLibraryAPI2" : 21
     Suggestion for "SampleLibraryAPI2"         : Did you mean interface "SampleLibraryAP2"?
     Fix                                        : Add public API declaration(s) "SampleLibraryAPI1", "SampleLibraryAPI2" in the public API diagram, or remove those interface declarations from the static diagram.
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/public_api.puml b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/public_api.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/public_api.puml
rename to validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/public_api.puml
diff --git a/validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/static_design.puml b/validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/static_design.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/negative_public_api_missing_with_suggestions/static_design.puml
rename to validation/core/integration_test/component_public_api/negative_public_apis_missing_from_public_api_diagram_with_suggestions/static_design.puml
diff --git a/validation/core/integration_test/component_public_api/positive_public_api_match/BUILD b/validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc/BUILD
similarity index 100%
rename from validation/core/integration_test/component_public_api/positive_public_api_match/BUILD
rename to validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc/BUILD
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/expected.yaml b/validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc/expected.yaml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/positive_participant_alias_display_name_namespace_match/expected.yaml
rename to validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc/expected.yaml
diff --git a/validation/core/integration_test/component_public_api/positive_public_api_match/public_api.puml b/validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc/public_api.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/positive_public_api_match/public_api.puml
rename to validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc/public_api.puml
diff --git a/validation/core/integration_test/component_public_api/positive_public_api_match/static_design.puml b/validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc/static_design.puml
similarity index 100%
rename from validation/core/integration_test/component_public_api/positive_public_api_match/static_design.puml
rename to validation/core/integration_test/component_public_api/positive_public_api_declared_and_related_to_seooc/static_design.puml
diff --git a/validation/core/integration_test/component_sequence/BUILD b/validation/core/integration_test/component_sequence/BUILD
index b0ef8c45..7754df7e 100644
--- a/validation/core/integration_test/component_sequence/BUILD
+++ b/validation/core/integration_test/component_sequence/BUILD
@@ -16,15 +16,12 @@ load("@rules_rust//rust:defs.bzl", "rust_test")
 filegroup(
     name = "component_sequence_test_data",
     srcs = [
-        "//validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units:case_data",
-        "//validation/core/integration_test/component_sequence/negative_missing_participant:case_data",
-        "//validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units:case_data",
-        "//validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation:case_data",
-        "//validation/core/integration_test/component_sequence/negative_mixed_mismatch:case_data",
-        "//validation/core/integration_test/component_sequence/negative_orphan_participant:case_data",
-        "//validation/core/integration_test/component_sequence/positive_exact_match:case_data",
-        "//validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return:case_data",
-        "//validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection:case_data",
+        "//validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence:case_data",
+        "//validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface:case_data",
+        "//validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call:case_data",
+        "//validation/core/integration_test/component_sequence/positive_external_callee_return_allowed:case_data",
+        "//validation/core/integration_test/component_sequence/positive_external_caller_call_allowed:case_data",
+        "//validation/core/integration_test/component_sequence/positive_matching_component_and_sequence:case_data",
         "//validation/core/integration_test/component_sequence/positive_overview_preserves_unit_bindings:case_data",
     ],
 )
diff --git a/validation/core/integration_test/component_sequence/component_sequence_suite.rs b/validation/core/integration_test/component_sequence/component_sequence_suite.rs
index 8407382e..fb50123e 100644
--- a/validation/core/integration_test/component_sequence/component_sequence_suite.rs
+++ b/validation/core/integration_test/component_sequence/component_sequence_suite.rs
@@ -52,8 +52,8 @@ fn assert_case(case_dir: &str) {
 }
 
 #[test]
-fn positive_exact_match_suite_case() {
-    assert_case("positive_exact_match");
+fn positive_matching_component_and_sequence_suite_case() {
+    assert_case("positive_matching_component_and_sequence");
 }
 
 #[test]
@@ -62,41 +62,26 @@ fn positive_overview_preserves_unit_bindings_suite_case() {
 }
 
 #[test]
-fn negative_missing_participant_suite_case() {
-    assert_case("negative_missing_participant");
+fn negative_component_unit_missing_from_sequence_suite_case() {
+    assert_case("negative_component_unit_missing_from_sequence");
 }
 
 #[test]
-fn positive_external_caller_in_sequence_connection_suite_case() {
-    assert_case("positive_external_caller_in_sequence_connection");
+fn positive_external_caller_call_allowed_suite_case() {
+    assert_case("positive_external_caller_call_allowed");
 }
 
 #[test]
-fn positive_external_callee_in_sequence_return_suite_case() {
-    assert_case("positive_external_callee_in_sequence_return");
+fn positive_external_callee_return_allowed_suite_case() {
+    assert_case("positive_external_callee_return_allowed");
 }
 
 #[test]
-fn negative_missing_interface_connection_for_sequence_connected_units_suite_case() {
-    assert_case("negative_missing_interface_connection_for_sequence_connected_units");
+fn negative_sequence_call_without_shared_interface_suite_case() {
+    assert_case("negative_sequence_call_without_shared_interface");
 }
 
 #[test]
-fn negative_missing_sequence_interaction_for_interface_connected_units_suite_case() {
-    assert_case("negative_missing_sequence_interaction_for_interface_connected_units");
-}
-
-#[test]
-fn negative_missing_unit_interface_relation_suite_case() {
-    assert_case("negative_missing_unit_interface_relation");
-}
-
-#[test]
-fn negative_orphan_participant_suite_case() {
-    assert_case("negative_orphan_participant");
-}
-
-#[test]
-fn negative_mixed_mismatch_suite_case() {
-    assert_case("negative_mixed_mismatch");
+fn negative_shared_interface_without_sequence_call_suite_case() {
+    assert_case("negative_shared_interface_without_sequence_call");
 }
diff --git a/validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/BUILD b/validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/BUILD
similarity index 100%
rename from validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/BUILD
rename to validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/BUILD
diff --git a/validation/core/integration_test/component_sequence/negative_missing_participant/component_diagram.puml b/validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_sequence/negative_missing_participant/component_diagram.puml
rename to validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/component_diagram.puml
diff --git a/validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/expected.yaml b/validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/expected.yaml
new file mode 100644
index 00000000..20818be9
--- /dev/null
+++ b/validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/expected.yaml
@@ -0,0 +1,20 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+should_pass: false
+error_contains: |
+  [Naming] Unit id "package_a.component_a.unit_3" from the component diagram not found as a participant uid in the sequence diagram.
+    Unit id                                       : "package_a.component_a.unit_3"
+    Component source file                         : "validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/component_diagram.puml"
+    Component source line                         : 20
+    Suggestion for "package_a.component_a.unit_3" : Did you mean "package_a.component_a.unit_1"?
+    Fix                                           : Add sequence participant uid "package_a.component_a.unit_3" in the sequence diagram, or remove it from the component diagram.
diff --git a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/sequence_diagram.puml b/validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/sequence_diagram.puml
similarity index 80%
rename from validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/sequence_diagram.puml
rename to validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/sequence_diagram.puml
index f2324391..371dc5f6 100644
--- a/validation/core/integration_test/class_design_sequence/negative_participant_special_display_multiple_colons/sequence_diagram.puml
+++ b/validation/core/integration_test/component_sequence/negative_component_unit_missing_from_sequence/sequence_diagram.puml
@@ -13,6 +13,7 @@
 
 @startuml sequence_diagram
 
-participant "instance:score::mw::com::impl::Runtime:Impl"
+participant "Unit 1 : package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "Unit 2 : package_a::component_a::unit_2" as unit_2 <<unit>>
 
 @enduml
diff --git a/validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/expected.yaml b/validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/expected.yaml
deleted file mode 100644
index e0e0351a..00000000
--- a/validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/expected.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains: |
-  [Interface] Sequence-connected units "unit_1" and "unit_2" have no corresponding shared interface connection in the component diagram.
-    Unit pair               : "unit_1" <-> "unit_2"
-    Sequence source file    : "validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/sequence_diagram.puml"
-    Sequence source line    : 19
-    Interfaces for "unit_1" : "package_a.CallerInterface"
-    Interfaces for "unit_2" : "package_a.CalleeInterface"
-    Fix                     : Add a shared interface connection between "unit_1" and "unit_2" in the component diagram, or remove that function-call from the sequence diagram.
diff --git a/validation/core/integration_test/component_sequence/negative_missing_participant/expected.yaml b/validation/core/integration_test/component_sequence/negative_missing_participant/expected.yaml
deleted file mode 100644
index dacfca76..00000000
--- a/validation/core/integration_test/component_sequence/negative_missing_participant/expected.yaml
+++ /dev/null
@@ -1,29 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains:
-  - |
-    [Naming] Alias "unit_3" from the component diagram not found in the sequence diagram.
-      Alias                   : "unit_3"
-      Component source file   : "validation/core/integration_test/component_sequence/negative_missing_participant/component_diagram.puml"
-      Component source line   : 20
-      Suggestion for "unit_3" : Did you mean "unit_1"?
-      Fix                     : Add sequence participant "unit_3" in the sequence diagram, or remove it from the component diagram.
-  - |
-    [Interface] Sequence-connected units "unit_1" and "unit_2" have no corresponding shared interface connection in the component diagram.
-      Unit pair               : "unit_1" <-> "unit_2"
-      Sequence source file    : "validation/core/integration_test/component_sequence/negative_missing_participant/sequence_diagram.puml"
-      Sequence source line    : 19
-      Interfaces for "unit_1" : <none>
-      Interfaces for "unit_2" : <none>
-      Fix                     : Add a shared interface connection between "unit_1" and "unit_2" in the component diagram, or remove that function-call from the sequence diagram.
diff --git a/validation/core/integration_test/component_sequence/negative_missing_participant/sequence_diagram.puml b/validation/core/integration_test/component_sequence/negative_missing_participant/sequence_diagram.puml
deleted file mode 100644
index 13fb581c..00000000
--- a/validation/core/integration_test/component_sequence/negative_missing_participant/sequence_diagram.puml
+++ /dev/null
@@ -1,21 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml sequence_diagram
-
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
-
-unit_1 -> unit_2 : Poll
-
-@enduml
diff --git a/validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/expected.yaml b/validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/expected.yaml
deleted file mode 100644
index 7983f68e..00000000
--- a/validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/expected.yaml
+++ /dev/null
@@ -1,22 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains: |
-  [Interface] Component-connected units "unit_1" and "unit_2" have no corresponding function-call in the sequence diagram.
-    Unit pair                          : "unit_1" <-> "unit_2"
-    Component source file for "unit_1" : "validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/component_diagram.puml"
-    Component source line for "unit_1" : 18
-    Component source file for "unit_2" : "validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/component_diagram.puml"
-    Component source line for "unit_2" : 19
-    Shared interfaces                  : "package_a.InternalInterface"
-    Fix                                : Add a function-call between "unit_1" and "unit_2" in the sequence diagram, or remove that shared interface connection from the component diagram.
diff --git a/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/component_diagram.puml b/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/component_diagram.puml
deleted file mode 100644
index 0cb1c4db..00000000
--- a/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/component_diagram.puml
+++ /dev/null
@@ -1,26 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml component_diagram
-
-package "Package A" as package_a {
-    component "Component A" as component_a <<component>> {
-        component "Unit 1" as unit_1 <<unit>>
-        component "Unit 2" as unit_2 <<unit>>
-    }
-
-    interface "InternalInterface" as InternalInterface
-    unit_2 )- InternalInterface
-}
-
-@enduml
diff --git a/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/expected.yaml b/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/expected.yaml
deleted file mode 100644
index 2c3d2afd..00000000
--- a/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/expected.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains: |
-  [Interface] Sequence-connected units "unit_1" and "unit_2" have no corresponding shared interface connection in the component diagram.
-    Unit pair               : "unit_1" <-> "unit_2"
-    Sequence source file    : "validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/sequence_diagram.puml"
-    Sequence source line    : 19
-    Interfaces for "unit_1" : <none>
-    Interfaces for "unit_2" : "package_a.InternalInterface"
-    Fix                     : Add a shared interface connection between "unit_1" and "unit_2" in the component diagram, or remove that function-call from the sequence diagram.
diff --git a/validation/core/integration_test/component_sequence/negative_mixed_mismatch/component_diagram.puml b/validation/core/integration_test/component_sequence/negative_mixed_mismatch/component_diagram.puml
deleted file mode 100644
index fc7b05ef..00000000
--- a/validation/core/integration_test/component_sequence/negative_mixed_mismatch/component_diagram.puml
+++ /dev/null
@@ -1,23 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml component_diagram
-
-package "Package A" as package_a {
-    component "Component A" as component_a <<component>> {
-        component "Unit 1" as unit_1 <<unit>>
-        component "Unit 2" as unit_2 <<unit>>
-    }
-}
-
-@enduml
diff --git a/validation/core/integration_test/component_sequence/negative_mixed_mismatch/expected.yaml b/validation/core/integration_test/component_sequence/negative_mixed_mismatch/expected.yaml
deleted file mode 100644
index 62faf753..00000000
--- a/validation/core/integration_test/component_sequence/negative_mixed_mismatch/expected.yaml
+++ /dev/null
@@ -1,36 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains:
-  - |
-    [Naming] Alias "unit_1" from the component diagram not found in the sequence diagram.
-      Alias                   : "unit_1"
-      Component source file   : "validation/core/integration_test/component_sequence/negative_mixed_mismatch/component_diagram.puml"
-      Component source line   : 18
-      Suggestion for "unit_1" : Did you mean "unit_2"?
-      Fix                     : Add sequence participant "unit_1" in the sequence diagram, or remove it from the component diagram.
-  - |
-    [Naming] Participant "unit_3" from the sequence diagram not found in the component diagram.
-      Participant             : "unit_3"
-      Sequence source file    : "validation/core/integration_test/component_sequence/negative_mixed_mismatch/sequence_diagram.puml"
-      Sequence source line    : 17
-      Suggestion for "unit_3" : Did you mean "unit_1"?
-      Fix                     : Add component unit alias "unit_3" in the component diagram, or remove it from the sequence diagram.
-  - |
-    [Interface] Sequence-connected units "unit_2" and "unit_3" have no corresponding shared interface connection in the component diagram.
-      Unit pair               : "unit_2" <-> "unit_3"
-      Sequence source file    : "validation/core/integration_test/component_sequence/negative_mixed_mismatch/sequence_diagram.puml"
-      Sequence source line    : 19
-      Interfaces for "unit_2" : <none>
-      Interfaces for "unit_3" : <none>
-      Fix                     : Add a shared interface connection between "unit_2" and "unit_3" in the component diagram, or remove that function-call from the sequence diagram.
diff --git a/validation/core/integration_test/component_sequence/negative_mixed_mismatch/sequence_diagram.puml b/validation/core/integration_test/component_sequence/negative_mixed_mismatch/sequence_diagram.puml
deleted file mode 100644
index fc6fb34d..00000000
--- a/validation/core/integration_test/component_sequence/negative_mixed_mismatch/sequence_diagram.puml
+++ /dev/null
@@ -1,21 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml sequence_diagram
-
-participant "Unit 2" as unit_2 <<unit>>
-participant "Unit 3" as unit_3 <<unit>>
-
-unit_2 -> unit_3 : Relay
-
-@enduml
diff --git a/validation/core/integration_test/component_sequence/negative_orphan_participant/BUILD b/validation/core/integration_test/component_sequence/negative_orphan_participant/BUILD
deleted file mode 100644
index 86cd716f..00000000
--- a/validation/core/integration_test/component_sequence/negative_orphan_participant/BUILD
+++ /dev/null
@@ -1,38 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "architectural_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-architectural_design(
-    name = "design",
-    dynamic = ["sequence_diagram.puml"],
-    maturity = "development",
-    static = ["component_diagram.puml"],
-    visibility = ["//visibility:private"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:public"],
-    deps = [":design"],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//visibility:public"],
-)
diff --git a/validation/core/integration_test/component_sequence/negative_orphan_participant/component_diagram.puml b/validation/core/integration_test/component_sequence/negative_orphan_participant/component_diagram.puml
deleted file mode 100644
index 5fb313f0..00000000
--- a/validation/core/integration_test/component_sequence/negative_orphan_participant/component_diagram.puml
+++ /dev/null
@@ -1,22 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml component_diagram
-
-package "Package A" as package_a {
-    component "Component A" as component_a <<component>> {
-        component "Unit 1" as unit_1 <<unit>>
-    }
-}
-
-@enduml
diff --git a/validation/core/integration_test/component_sequence/negative_orphan_participant/expected.yaml b/validation/core/integration_test/component_sequence/negative_orphan_participant/expected.yaml
deleted file mode 100644
index fae4db1f..00000000
--- a/validation/core/integration_test/component_sequence/negative_orphan_participant/expected.yaml
+++ /dev/null
@@ -1,29 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains:
-  - |
-    [Naming] Participant "unit_3" from the sequence diagram not found in the component diagram.
-      Participant             : "unit_3"
-      Sequence source file    : "validation/core/integration_test/component_sequence/negative_orphan_participant/sequence_diagram.puml"
-      Sequence source line    : 17
-      Suggestion for "unit_3" : Did you mean "unit_1"?
-      Fix                     : Add component unit alias "unit_3" in the component diagram, or remove it from the sequence diagram.
-  - |
-    [Interface] Sequence-connected units "unit_1" and "unit_3" have no corresponding shared interface connection in the component diagram.
-      Unit pair               : "unit_1" <-> "unit_3"
-      Sequence source file    : "validation/core/integration_test/component_sequence/negative_orphan_participant/sequence_diagram.puml"
-      Sequence source line    : 19
-      Interfaces for "unit_1" : <none>
-      Interfaces for "unit_3" : <none>
-      Fix                     : Add a shared interface connection between "unit_1" and "unit_3" in the component diagram, or remove that function-call from the sequence diagram.
diff --git a/validation/core/integration_test/component_sequence/negative_orphan_participant/sequence_diagram.puml b/validation/core/integration_test/component_sequence/negative_orphan_participant/sequence_diagram.puml
deleted file mode 100644
index 09191d95..00000000
--- a/validation/core/integration_test/component_sequence/negative_orphan_participant/sequence_diagram.puml
+++ /dev/null
@@ -1,21 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml sequence_diagram
-
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 3" as unit_3 <<unit>>
-
-unit_1 -> unit_3 : UnknownCall
-
-@enduml
diff --git a/validation/core/integration_test/component_sequence/negative_missing_participant/BUILD b/validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/BUILD
similarity index 100%
rename from validation/core/integration_test/component_sequence/negative_missing_participant/BUILD
rename to validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/BUILD
diff --git a/validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/component_diagram.puml b/validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/component_diagram.puml
rename to validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/component_diagram.puml
diff --git a/validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/expected.yaml b/validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/expected.yaml
new file mode 100644
index 00000000..7f6ffc01
--- /dev/null
+++ b/validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/expected.yaml
@@ -0,0 +1,21 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+should_pass: false
+error_contains: |
+  [Interface] Sequence-connected units "package_a.component_a.unit_1" and "package_a.component_a.unit_2" have no corresponding shared interface connection in the component diagram.
+    Unit pair                                     : "package_a.component_a.unit_1" <-> "package_a.component_a.unit_2"
+    Sequence source file                          : "validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/sequence_diagram.puml"
+    Sequence source line                          : 19
+    Interfaces for "package_a.component_a.unit_1" : "package_a.CallerInterface"
+    Interfaces for "package_a.component_a.unit_2" : "package_a.CalleeInterface"
+    Fix                                           : Add a shared interface connection between "package_a.component_a.unit_1" and "package_a.component_a.unit_2" in the component diagram, or remove that function-call from the sequence diagram.
diff --git a/validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/sequence_diagram.puml b/validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/sequence_diagram.puml
similarity index 81%
rename from validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/sequence_diagram.puml
rename to validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/sequence_diagram.puml
index 32938db5..77a0597b 100644
--- a/validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/sequence_diagram.puml
+++ b/validation/core/integration_test/component_sequence/negative_sequence_call_without_shared_interface/sequence_diagram.puml
@@ -13,8 +13,8 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "Unit 1 : package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "Unit 2 : package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : GetData()
 unit_2 --> unit_1 : Ack
diff --git a/validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/BUILD b/validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/BUILD
similarity index 100%
rename from validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/BUILD
rename to validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/BUILD
diff --git a/validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/component_diagram.puml b/validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/component_diagram.puml
rename to validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/component_diagram.puml
diff --git a/validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/expected.yaml b/validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/expected.yaml
new file mode 100644
index 00000000..876aeff1
--- /dev/null
+++ b/validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/expected.yaml
@@ -0,0 +1,22 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+should_pass: false
+error_contains: |
+  [Interface] Component-connected units "package_a.component_a.unit_1" and "package_a.component_a.unit_2" have no corresponding function-call in the sequence diagram.
+    Unit pair                                                : "package_a.component_a.unit_1" <-> "package_a.component_a.unit_2"
+    Component source file for "package_a.component_a.unit_1" : "validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/component_diagram.puml"
+    Component source line for "package_a.component_a.unit_1" : 18
+    Component source file for "package_a.component_a.unit_2" : "validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/component_diagram.puml"
+    Component source line for "package_a.component_a.unit_2" : 19
+    Shared interfaces                                        : "package_a.InternalInterface"
+    Fix                                                      : Add a function-call between "package_a.component_a.unit_1" and "package_a.component_a.unit_2" in the sequence diagram, or remove that shared interface connection from the component diagram.
diff --git a/validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/sequence_diagram.puml b/validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/sequence_diagram.puml
similarity index 81%
rename from validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/sequence_diagram.puml
rename to validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/sequence_diagram.puml
index 0d5e55db..dc713751 100644
--- a/validation/core/integration_test/component_sequence/negative_missing_sequence_interaction_for_interface_connected_units/sequence_diagram.puml
+++ b/validation/core/integration_test/component_sequence/negative_shared_interface_without_sequence_call/sequence_diagram.puml
@@ -13,8 +13,8 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "Unit 1 : package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "Unit 2 : package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_1 : Poll
 unit_2 -> unit_2 : Tick
diff --git a/validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/BUILD b/validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/BUILD
deleted file mode 100644
index 86cd716f..00000000
--- a/validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/BUILD
+++ /dev/null
@@ -1,38 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "architectural_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-architectural_design(
-    name = "design",
-    dynamic = ["sequence_diagram.puml"],
-    maturity = "development",
-    static = ["component_diagram.puml"],
-    visibility = ["//visibility:private"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:public"],
-    deps = [":design"],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//visibility:public"],
-)
diff --git a/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/BUILD b/validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/BUILD
similarity index 100%
rename from validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/BUILD
rename to validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/BUILD
diff --git a/validation/core/integration_test/component_internal_api/positive_interface_match/component_diagram.puml b/validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_internal_api/positive_interface_match/component_diagram.puml
rename to validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/component_diagram.puml
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/expected.yaml b/validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/expected.yaml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/positive_participant_short_name_namespace_match/expected.yaml
rename to validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/expected.yaml
diff --git a/validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/sequence_diagram.puml b/validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/sequence_diagram.puml
new file mode 100644
index 00000000..2556e302
--- /dev/null
+++ b/validation/core/integration_test/component_sequence/positive_external_callee_return_allowed/sequence_diagram.puml
@@ -0,0 +1,22 @@
+' *******************************************************************************
+' Copyright (c) 2026 Contributors to the Eclipse Foundation
+'
+' See the NOTICE file(s) distributed with this work for additional
+' information regarding copyright ownership.
+'
+' This program and the accompanying materials are made available under the
+' terms of the Apache License Version 2.0 which is available at
+' https://www.apache.org/licenses/LICENSE-2.0
+'
+' SPDX-License-Identifier: Apache-2.0
+' *******************************************************************************
+
+@startuml sequence_diagram
+
+participant "Unit 1 : package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "Unit 2 : package_a::component_a::unit_2" as unit_2 <<unit>>
+
+unit_1 -> unit_2 : GetData()
+--> unit_1 : Ack
+
+@enduml
diff --git a/validation/core/integration_test/component_sequence/negative_mixed_mismatch/BUILD b/validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/BUILD
similarity index 100%
rename from validation/core/integration_test/component_sequence/negative_mixed_mismatch/BUILD
rename to validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/BUILD
diff --git a/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/component_diagram.puml b/validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/component_diagram.puml
rename to validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/component_diagram.puml
diff --git a/validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/expected.yaml b/validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/expected.yaml
similarity index 100%
rename from validation/core/integration_test/class_design_sequence/positive_participant_special_display_encoded_newline_match/expected.yaml
rename to validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/expected.yaml
diff --git a/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/sequence_diagram.puml b/validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/sequence_diagram.puml
similarity index 89%
rename from validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/sequence_diagram.puml
rename to validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/sequence_diagram.puml
index 07bb911c..2d8d4b61 100644
--- a/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/sequence_diagram.puml
+++ b/validation/core/integration_test/component_sequence/positive_external_caller_call_allowed/sequence_diagram.puml
@@ -13,7 +13,7 @@
 
 @startuml sequence_diagram
 
-participant "Unit 2" as unit_2 <<unit>>
+participant "Unit 2 : package_a::component_a::unit_2" as unit_2 <<unit>>
 
 -> unit_2 : GetData()
 
diff --git a/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/BUILD b/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/BUILD
deleted file mode 100644
index 86cd716f..00000000
--- a/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/BUILD
+++ /dev/null
@@ -1,38 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-load("//bazel/rules/rules_score:rules_score.bzl", "architectural_design")
-load("//validation/core/integration_test:puml_fixture.bzl", "provider_fbs_fixture_bundle")
-
-architectural_design(
-    name = "design",
-    dynamic = ["sequence_diagram.puml"],
-    maturity = "development",
-    static = ["component_diagram.puml"],
-    visibility = ["//visibility:private"],
-)
-
-provider_fbs_fixture_bundle(
-    name = "fbs",
-    visibility = ["//visibility:public"],
-    deps = [":design"],
-)
-
-filegroup(
-    name = "case_data",
-    srcs = [
-        "expected.yaml",
-        ":fbs",
-    ],
-    visibility = ["//visibility:public"],
-)
diff --git a/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/expected.yaml b/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/expected.yaml
deleted file mode 100644
index 898ecba3..00000000
--- a/validation/core/integration_test/component_sequence/positive_external_caller_in_sequence_connection/expected.yaml
+++ /dev/null
@@ -1,13 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: true
diff --git a/validation/core/integration_test/component_sequence/positive_exact_match/BUILD b/validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/BUILD
similarity index 100%
rename from validation/core/integration_test/component_sequence/positive_exact_match/BUILD
rename to validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/BUILD
diff --git a/validation/core/integration_test/component_sequence/positive_exact_match/component_diagram.puml b/validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_sequence/positive_exact_match/component_diagram.puml
rename to validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/component_diagram.puml
diff --git a/validation/core/integration_test/component_internal_api/positive_interface_match/expected.yaml b/validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/expected.yaml
similarity index 100%
rename from validation/core/integration_test/component_internal_api/positive_interface_match/expected.yaml
rename to validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/expected.yaml
diff --git a/validation/core/integration_test/component_sequence/positive_exact_match/sequence_diagram.puml b/validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/sequence_diagram.puml
similarity index 81%
rename from validation/core/integration_test/component_sequence/positive_exact_match/sequence_diagram.puml
rename to validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/sequence_diagram.puml
index fcca6a92..a7b3247f 100644
--- a/validation/core/integration_test/component_sequence/positive_exact_match/sequence_diagram.puml
+++ b/validation/core/integration_test/component_sequence/positive_matching_component_and_sequence/sequence_diagram.puml
@@ -13,8 +13,8 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "Unit 1 : package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "Unit 2 : package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : SendSignal
 unit_2 --> unit_1 : Ack
diff --git a/validation/core/integration_test/component_sequence/positive_overview_preserves_unit_bindings/sequence_diagram.puml b/validation/core/integration_test/component_sequence/positive_overview_preserves_unit_bindings/sequence_diagram.puml
index fcca6a92..a7b3247f 100644
--- a/validation/core/integration_test/component_sequence/positive_overview_preserves_unit_bindings/sequence_diagram.puml
+++ b/validation/core/integration_test/component_sequence/positive_overview_preserves_unit_bindings/sequence_diagram.puml
@@ -13,8 +13,8 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "Unit 1 : package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "Unit 2 : package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : SendSignal
 unit_2 --> unit_1 : Ack
diff --git a/validation/core/integration_test/sequence_internal_api/BUILD b/validation/core/integration_test/sequence_internal_api/BUILD
index f73ba901..6888e99f 100644
--- a/validation/core/integration_test/sequence_internal_api/BUILD
+++ b/validation/core/integration_test/sequence_internal_api/BUILD
@@ -16,11 +16,11 @@ load("@rules_rust//rust:defs.bzl", "rust_test")
 filegroup(
     name = "sequence_internal_api_test_data",
     srcs = [
-        "//validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised:case_data",
-        "//validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction:case_data",
-        "//validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface:case_data",
-        "//validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion:case_data",
-        "//validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface:case_data",
+        "//validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised:case_data",
+        "//validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface:case_data",
+        "//validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion:case_data",
+        "//validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface:case_data",
+        "//validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch:case_data",
         "//validation/core/integration_test/sequence_internal_api/positive_internal_api_method_match:case_data",
         "//validation/core/integration_test/sequence_internal_api/positive_self_call_method_match:case_data",
     ],
diff --git a/validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/BUILD b/validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/BUILD
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/BUILD
rename to validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/BUILD
diff --git a/validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/component_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/component_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/component_diagram.puml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/expected.yaml b/validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/expected.yaml
similarity index 92%
rename from validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/expected.yaml
rename to validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/expected.yaml
index 6e14df3a..da273b3a 100644
--- a/validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/expected.yaml
+++ b/validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/expected.yaml
@@ -14,7 +14,7 @@ should_pass: false
 error_contains: |
   [Coverage] Methods "SetData" declared on internal API interface "package_a.InternalInterface" in the internal API diagram are not exercised in the sequence diagram.
     Interface id             : "package_a.InternalInterface"
-    Internal API source file : "validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/internal_api_diagram.puml"
+    Internal API source file : "validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/internal_api_diagram.puml"
     Internal API source line : 17
     Missing functions        : "SetData"
     Fix                      : Add sequence interactions for functions "SetData" in the sequence diagram, or remove function declarations "SetData" in internal API interface "package_a.InternalInterface".
diff --git a/validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/internal_api_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/internal_api_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/internal_api_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/internal_api_diagram.puml
diff --git a/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/sequence_diagram.puml
similarity index 83%
rename from validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/sequence_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/sequence_diagram.puml
index 32938db5..fb7541f5 100644
--- a/validation/core/integration_test/component_sequence/negative_missing_unit_interface_relation/sequence_diagram.puml
+++ b/validation/core/integration_test/sequence_internal_api/negative_internal_api_method_not_exercised/sequence_diagram.puml
@@ -13,10 +13,9 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : GetData()
-unit_2 --> unit_1 : Ack
 
 @enduml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/expected.yaml b/validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/expected.yaml
deleted file mode 100644
index d972d6b0..00000000
--- a/validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/expected.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains: |
-  [Interface] Sequence call "unit_2" -> "unit_1" : "SendSignal" in the sequence diagram does not match the required/provided interface roles in the component diagram.
-    Sequence call        : "unit_2" -> "unit_1" : "SendSignal"
-    Sequence source file : "validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/sequence_diagram.puml"
-    Sequence source line : 19
-    Expected caller role : "unit_2" should require shared interface(s) "package_a.InternalInterface"
-    Expected callee role : "unit_1" should provide shared interface(s) "package_a.InternalInterface"
-    Fix                  : Add required/provided interface bindings for shared interface(s) "package_a.InternalInterface" in the component diagram, or remove sequence call "unit_2" -> "unit_1" : "SendSignal" in the sequence diagram.
diff --git a/validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/BUILD b/validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/BUILD
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/BUILD
rename to validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/BUILD
diff --git a/validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/component_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/component_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/component_diagram.puml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/expected.yaml b/validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/expected.yaml
similarity index 63%
rename from validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/expected.yaml
rename to validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/expected.yaml
index f66dcff6..8f0d6af7 100644
--- a/validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/expected.yaml
+++ b/validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/expected.yaml
@@ -12,9 +12,9 @@
 # *******************************************************************************
 should_pass: false
 error_contains: |
-  [Method] Sequence function "GetData" from sequence call "unit_1" -> "unit_2" : "GetData" in the sequence diagram not found in the internal API diagram.
-    Sequence call        : "unit_1" -> "unit_2" : "GetData"
-    Sequence source file : "validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/sequence_diagram.puml"
+  [Method] Sequence function "GetData" from sequence call "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData" in the sequence diagram not found in the internal API diagram.
+    Sequence call        : "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData"
+    Sequence source file : "validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/sequence_diagram.puml"
     Sequence source line : 19
     Detail               : sequence function name was not found in the related interface methods
-    Fix                  : Add method "GetData" in a matching internal API interface in the internal API diagram, or remove sequence function "GetData" in sequence call "unit_1" -> "unit_2" : "GetData" in the sequence diagram.
+    Fix                  : Add method "GetData" in a matching internal API interface in the internal API diagram, or remove sequence function "GetData" in sequence call "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData" in the sequence diagram.
diff --git a/validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/internal_api_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/internal_api_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/internal_api_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/internal_api_diagram.puml
diff --git a/validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/sequence_diagram.puml
similarity index 83%
rename from validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/sequence_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/sequence_diagram.puml
index 072dcc9b..fb7541f5 100644
--- a/validation/core/integration_test/component_sequence/positive_external_callee_in_sequence_return/sequence_diagram.puml
+++ b/validation/core/integration_test/sequence_internal_api/negative_method_declared_on_unrelated_interface/sequence_diagram.puml
@@ -13,10 +13,9 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : GetData()
---> unit_1 : Ack
 
 @enduml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/BUILD b/validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/BUILD
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_method_available_but_not_on_related_interface/BUILD
rename to validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/BUILD
diff --git a/validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/component_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/component_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/component_diagram.puml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/expected.yaml b/validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/expected.yaml
new file mode 100644
index 00000000..26c19570
--- /dev/null
+++ b/validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/expected.yaml
@@ -0,0 +1,21 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+should_pass: false
+error_contains: |
+  [Method] Sequence function "GetData" from sequence call "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData" in the sequence diagram not found in the internal API diagram.
+    Sequence call            : "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData"
+    Sequence source file     : "validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/sequence_diagram.puml"
+    Sequence source line     : 19
+    Detail                   : sequence function name was not found in available interface methods
+    Suggestion for "GetData" : Did you mean method "GetDate"?
+    Fix                      : Add method "GetData" in a matching internal API interface in the internal API diagram, or remove sequence function "GetData" in sequence call "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData" in the sequence diagram.
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/internal_api_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/internal_api_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/internal_api_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/internal_api_diagram.puml
diff --git a/validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/sequence_diagram.puml
similarity index 83%
rename from validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/sequence_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/sequence_diagram.puml
index 32938db5..fb7541f5 100644
--- a/validation/core/integration_test/component_sequence/negative_missing_interface_connection_for_sequence_connected_units/sequence_diagram.puml
+++ b/validation/core/integration_test/sequence_internal_api/negative_method_missing_with_suggestion/sequence_diagram.puml
@@ -13,10 +13,9 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : GetData()
-unit_2 --> unit_1 : Ack
 
 @enduml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/BUILD b/validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/BUILD
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/BUILD
rename to validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/BUILD
diff --git a/validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/component_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/component_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/component_diagram.puml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/expected.yaml b/validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/expected.yaml
new file mode 100644
index 00000000..a7152148
--- /dev/null
+++ b/validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/expected.yaml
@@ -0,0 +1,20 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+should_pass: false
+error_contains: |
+  [Method] Sequence function "GetData" from sequence call "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData" in the sequence diagram not found in the internal API diagram.
+    Sequence call        : "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData"
+    Sequence source file : "validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/sequence_diagram.puml"
+    Sequence source line : 19
+    Detail               : sequence function name was not found in available interface methods
+    Fix                  : Add method "GetData" in a matching internal API interface in the internal API diagram, or remove sequence function "GetData" in sequence call "package_a.component_a.unit_1" -> "package_a.component_a.unit_2" : "GetData" in the sequence diagram.
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/internal_api_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/internal_api_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/internal_api_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/internal_api_diagram.puml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/sequence_diagram.puml
similarity index 83%
rename from validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/sequence_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/sequence_diagram.puml
index 32938db5..fb7541f5 100644
--- a/validation/core/integration_test/sequence_internal_api/negative_interface_function_not_exercised/sequence_diagram.puml
+++ b/validation/core/integration_test/sequence_internal_api/negative_method_not_declared_in_related_interface/sequence_diagram.puml
@@ -13,10 +13,9 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : GetData()
-unit_2 --> unit_1 : Ack
 
 @enduml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/expected.yaml b/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/expected.yaml
deleted file mode 100644
index 36d0512f..00000000
--- a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/expected.yaml
+++ /dev/null
@@ -1,29 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains:
-  - |
-    [Method] Sequence function "GetData" from sequence call "unit_1" -> "unit_2" : "GetData" in the sequence diagram not found in the internal API diagram.
-      Sequence call            : "unit_1" -> "unit_2" : "GetData"
-      Sequence source file     : "validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/sequence_diagram.puml"
-      Sequence source line     : 19
-      Detail                   : sequence function name was not found in available interface methods
-      Suggestion for "GetData" : Did you mean method "GetDate"?
-      Fix                      : Add method "GetData" in a matching internal API interface in the internal API diagram, or remove sequence function "GetData" in sequence call "unit_1" -> "unit_2" : "GetData" in the sequence diagram.
-  - |-
-    [Coverage] Methods "GetDate" declared on internal API interface "package_a.InternalInterface" in the internal API diagram are not exercised in the sequence diagram.
-      Interface id             : "package_a.InternalInterface"
-      Internal API source file : "validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/internal_api_diagram.puml"
-      Internal API source line : 17
-      Missing functions        : "GetDate"
-      Fix                      : Add sequence interactions for functions "GetDate" in the sequence diagram, or remove function declarations "GetDate" in internal API interface "package_a.InternalInterface".
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/sequence_diagram.puml
deleted file mode 100644
index 32938db5..00000000
--- a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/sequence_diagram.puml
+++ /dev/null
@@ -1,22 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml sequence_diagram
-
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
-
-unit_1 -> unit_2 : GetData()
-unit_2 --> unit_1 : Ack
-
-@enduml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/component_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/component_diagram.puml
deleted file mode 100644
index c87543a4..00000000
--- a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/component_diagram.puml
+++ /dev/null
@@ -1,27 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml component_diagram
-
-package "Package A" as package_a {
-    component "Component A" as component_a <<component>> {
-        component "Unit 1" as unit_1 <<unit>>
-        component "Unit 2" as unit_2 <<unit>>
-    }
-
-    interface "InternalInterface" as InternalInterface
-    unit_1 -( InternalInterface
-    unit_2 )- InternalInterface
-}
-
-@enduml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/expected.yaml b/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/expected.yaml
deleted file mode 100644
index 5134e101..00000000
--- a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/expected.yaml
+++ /dev/null
@@ -1,28 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2026 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-should_pass: false
-error_contains:
-  - |
-    [Method] Sequence function "GetData" from sequence call "unit_1" -> "unit_2" : "GetData" in the sequence diagram not found in the internal API diagram.
-      Sequence call        : "unit_1" -> "unit_2" : "GetData"
-      Sequence source file : "validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/sequence_diagram.puml"
-      Sequence source line : 19
-      Detail               : sequence function name was not found in available interface methods
-      Fix                  : Add method "GetData" in a matching internal API interface in the internal API diagram, or remove sequence function "GetData" in sequence call "unit_1" -> "unit_2" : "GetData" in the sequence diagram.
-  - |
-    [Coverage] Methods "OtherMethod" declared on internal API interface "package_a.InternalInterface" in the internal API diagram are not exercised in the sequence diagram.
-      Interface id             : "package_a.InternalInterface"
-      Internal API source file : "validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/internal_api_diagram.puml"
-      Internal API source line : 17
-      Missing functions        : "OtherMethod"
-      Fix                      : Add sequence interactions for functions "OtherMethod" in the sequence diagram, or remove function declarations "OtherMethod" in internal API interface "package_a.InternalInterface".
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/sequence_diagram.puml
deleted file mode 100644
index 32938db5..00000000
--- a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/sequence_diagram.puml
+++ /dev/null
@@ -1,22 +0,0 @@
-' *******************************************************************************
-' Copyright (c) 2026 Contributors to the Eclipse Foundation
-'
-' See the NOTICE file(s) distributed with this work for additional
-' information regarding copyright ownership.
-'
-' This program and the accompanying materials are made available under the
-' terms of the Apache License Version 2.0 which is available at
-' https://www.apache.org/licenses/LICENSE-2.0
-'
-' SPDX-License-Identifier: Apache-2.0
-' *******************************************************************************
-
-@startuml sequence_diagram
-
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
-
-unit_1 -> unit_2 : GetData()
-unit_2 --> unit_1 : Ack
-
-@enduml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/BUILD b/validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/BUILD
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_missing_method_in_related_interface/BUILD
rename to validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/BUILD
diff --git a/validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/component_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/component_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_missing_method_in_available_interfaces_with_suggestion/component_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/component_diagram.puml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/expected.yaml b/validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/expected.yaml
new file mode 100644
index 00000000..d6a9caf7
--- /dev/null
+++ b/validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/expected.yaml
@@ -0,0 +1,21 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+should_pass: false
+error_contains: |
+  [Interface] Sequence call "package_a.component_a.unit_2" -> "package_a.component_a.unit_1" : "SendSignal" in the sequence diagram does not match the required/provided interface roles in the component diagram.
+    Sequence call        : "package_a.component_a.unit_2" -> "package_a.component_a.unit_1" : "SendSignal"
+    Sequence source file : "validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/sequence_diagram.puml"
+    Sequence source line : 19
+    Expected caller role : "package_a.component_a.unit_2" should require shared interface(s) "InternalInterface"
+    Expected callee role : "package_a.component_a.unit_1" should provide shared interface(s) "InternalInterface"
+    Fix                  : Add required/provided interface bindings for shared interface(s) "InternalInterface" in the component diagram, or remove sequence call "package_a.component_a.unit_2" -> "package_a.component_a.unit_1" : "SendSignal" in the sequence diagram.
diff --git a/validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/internal_api_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/internal_api_diagram.puml
similarity index 100%
rename from validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/internal_api_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/internal_api_diagram.puml
diff --git a/validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/sequence_diagram.puml
similarity index 83%
rename from validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/sequence_diagram.puml
rename to validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/sequence_diagram.puml
index 1b3f5286..67d82598 100644
--- a/validation/core/integration_test/sequence_internal_api/negative_invalid_consumer_provider_direction/sequence_diagram.puml
+++ b/validation/core/integration_test/sequence_internal_api/negative_sequence_call_direction_mismatch/sequence_diagram.puml
@@ -13,8 +13,8 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_2 -> unit_1 : SendSignal
 
diff --git a/validation/core/integration_test/sequence_internal_api/positive_internal_api_method_match/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/positive_internal_api_method_match/sequence_diagram.puml
index 89780326..25275aa7 100644
--- a/validation/core/integration_test/sequence_internal_api/positive_internal_api_method_match/sequence_diagram.puml
+++ b/validation/core/integration_test/sequence_internal_api/positive_internal_api_method_match/sequence_diagram.puml
@@ -13,8 +13,8 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
-participant "Unit 2" as unit_2 <<unit>>
+participant "package_a::component_a::unit_1" as unit_1 <<unit>>
+participant "package_a::component_a::unit_2" as unit_2 <<unit>>
 
 unit_1 -> unit_2 : GetData()
 return Ack
diff --git a/validation/core/integration_test/sequence_internal_api/positive_self_call_method_match/sequence_diagram.puml b/validation/core/integration_test/sequence_internal_api/positive_self_call_method_match/sequence_diagram.puml
index 8d5321d3..305dc2ec 100644
--- a/validation/core/integration_test/sequence_internal_api/positive_self_call_method_match/sequence_diagram.puml
+++ b/validation/core/integration_test/sequence_internal_api/positive_self_call_method_match/sequence_diagram.puml
@@ -13,7 +13,7 @@
 
 @startuml sequence_diagram
 
-participant "Unit 1" as unit_1 <<unit>>
+participant "package_a::component_a::unit_1" as unit_1 <<unit>>
 
 unit_1 -> unit_1 : GetData()
 
diff --git a/validation/core/integration_test/sequence_internal_api/sequence_internal_api_suite.rs b/validation/core/integration_test/sequence_internal_api/sequence_internal_api_suite.rs
index 6d146652..8ba94dbf 100644
--- a/validation/core/integration_test/sequence_internal_api/sequence_internal_api_suite.rs
+++ b/validation/core/integration_test/sequence_internal_api/sequence_internal_api_suite.rs
@@ -58,28 +58,28 @@ fn assert_case(case_dir: &str) {
 }
 
 #[test]
-fn negative_interface_function_not_exercised_suite_case() {
-    assert_case("negative_interface_function_not_exercised");
+fn negative_internal_api_method_not_exercised_suite_case() {
+    assert_case("negative_internal_api_method_not_exercised");
 }
 
 #[test]
-fn negative_invalid_consumer_provider_direction_suite_case() {
-    assert_case("negative_invalid_consumer_provider_direction");
+fn negative_sequence_call_direction_mismatch_suite_case() {
+    assert_case("negative_sequence_call_direction_mismatch");
 }
 
 #[test]
-fn negative_missing_method_in_related_interface_suite_case() {
-    assert_case("negative_missing_method_in_related_interface");
+fn negative_method_not_declared_in_related_interface_suite_case() {
+    assert_case("negative_method_not_declared_in_related_interface");
 }
 
 #[test]
-fn negative_missing_method_in_available_interfaces_with_suggestion_suite_case() {
-    assert_case("negative_missing_method_in_available_interfaces_with_suggestion");
+fn negative_method_missing_with_suggestion_suite_case() {
+    assert_case("negative_method_missing_with_suggestion");
 }
 
 #[test]
-fn negative_method_available_but_not_on_related_interface_suite_case() {
-    assert_case("negative_method_available_but_not_on_related_interface");
+fn negative_method_declared_on_unrelated_interface_suite_case() {
+    assert_case("negative_method_declared_on_unrelated_interface");
 }
 
 #[test]
diff --git a/validation/core/src/models/class_diagram_models.rs b/validation/core/src/models/class_diagram_models.rs
index 658b2105..2aff3566 100644
--- a/validation/core/src/models/class_diagram_models.rs
+++ b/validation/core/src/models/class_diagram_models.rs
@@ -18,6 +18,7 @@ use std::collections::{BTreeMap, BTreeSet};
 use class_diagram::{ClassDiagram as ClassDiagramInput, EntityType, SimpleEntity};
 use source_location::SourceLocation;
 
+use crate::validators::shared::display_entity_name;
 use crate::{ErrorBuilder, ErrorCategory, ValidationResult};
 
 /// Collection of class diagrams loaded from one or more FlatBuffer files.
@@ -35,27 +36,30 @@ impl ClassEntityIndex {
 
         for diagram in diagrams {
             for entity in &diagram.entities {
-                let indexed_entity = entity.clone();
+                let current_entity = entity.clone();
 
-                let key = indexed_entity.id.to_lowercase();
-                if let Some(prev) = entities.get(&key) {
-                    let (first_source_file, _) = prev.source_location.display();
-                    let (second_source_file, _) = indexed_entity.source_location.display();
+                let normalized_entity_id = current_entity.id.to_lowercase();
+                if let Some(existing_entity) = entities.get(&normalized_entity_id) {
+                    let (first_source_file, _) = existing_entity.source_location.display();
+                    let (second_source_file, _) = current_entity.source_location.display();
 
                     result.add_failure(
                         ErrorBuilder::new(ErrorCategory::Class)
                             .title(format!(
                                 "class \"{}\" is defined more than once in the class diagram.",
-                                prev.id,
+                                display_entity_name(existing_entity),
                             ))
-                            .field("class", format!("\"{}\"", prev.id))
+                            .field(
+                                "class",
+                                format!("\"{}\"", display_entity_name(existing_entity)),
+                            )
                             .field(
                                 "design source file",
                                 format!("\"{}\"", first_source_file),
                             )
                             .field(
                                 "design source line",
-                                prev.source_location.line.to_string(),
+                                existing_entity.source_location.line.to_string(),
                             )
                             .field(
                                 "duplicate source file",
@@ -63,16 +67,16 @@ impl ClassEntityIndex {
                             )
                             .field(
                                 "duplicate source line",
-                                indexed_entity.source_location.line.to_string(),
+                                current_entity.source_location.line.to_string(),
                             )
                             .fix(format!(
                                 "remove or rename one of the duplicate class \"{}\" declarations in the class diagram",
-                                prev.id,
+                                display_entity_name(existing_entity),
                             ))
                             .build(),
                     );
                 } else {
-                    entities.insert(key, indexed_entity);
+                    entities.insert(normalized_entity_id, current_entity);
                 }
             }
         }
@@ -137,13 +141,13 @@ impl InternalApiIndex {
 
 /// Indexed public-API data prepared for component/public-API validators.
 pub struct PublicApiIndex {
-    api_index: BTreeMap<String, String>, // <interface name, interface id>
+    api_ids: BTreeSet<String>,
 }
 
 impl PublicApiIndex {
     /// Build a [`PublicApiIndex`] from public-API class diagram inputs.
     pub fn build_index(diagrams: &[ClassDiagramInput]) -> Self {
-        let mut api_index: BTreeMap<String, String> = BTreeMap::new();
+        let mut api_ids = BTreeSet::new();
 
         for diagram in diagrams {
             for entity in &diagram.entities {
@@ -151,15 +155,15 @@ impl PublicApiIndex {
                     continue;
                 }
 
-                api_index.insert(entity.name.clone(), entity.id.clone());
+                api_ids.insert(entity.id.clone());
             }
         }
 
-        Self { api_index }
+        Self { api_ids }
     }
 
-    pub fn api_names(&self) -> impl Iterator<Item = &String> + '_ {
-        self.api_index.keys()
+    pub fn api_ids(&self) -> impl Iterator<Item = &String> + '_ {
+        self.api_ids.iter()
     }
 }
 
@@ -213,9 +217,8 @@ mod tests {
         let _index = ClassEntityIndex::build_index(&diagrams, &mut result);
 
         assert_eq!(result.failures.len(), 1);
-        assert!(result.failures[0].contains(
-            "[Class] Class \"Unit.Sample\" is defined more than once in the class diagram."
-        ));
+        assert!(result.failures[0]
+            .contains("[Class] Class \"Sample\" is defined more than once in the class diagram."));
     }
 
     #[test]
@@ -316,4 +319,50 @@ mod tests {
         assert!(interface_ids.contains("InternalAPI.InternalInterfaceA"));
         assert!(interface_ids.contains("InternalAPI.InternalInterfaceB"));
     }
+
+    #[test]
+    fn public_api_index_keeps_distinct_interface_ids_even_when_names_match() {
+        let diagrams = vec![ClassDiagram {
+            name: "public_api".to_string(),
+            entities: vec![
+                SimpleEntity {
+                    id: "ServiceA.SampleLibraryAPI".to_string(),
+                    name: "SampleLibraryAPI".to_string(),
+                    enclosing_namespace_id: Some("ServiceA".to_string()),
+                    stereotypes: Vec::new(),
+                    entity_type: EntityType::Interface,
+                    type_aliases: Vec::new(),
+                    variables: Vec::new(),
+                    methods: Vec::new(),
+                    template_parameters: None,
+                    enum_literals: Vec::new(),
+                    relationships: Vec::new(),
+                    source_location: SourceLocation::new("test_a.puml", 1),
+                },
+                SimpleEntity {
+                    id: "ServiceB.SampleLibraryAPI".to_string(),
+                    name: "SampleLibraryAPI".to_string(),
+                    enclosing_namespace_id: Some("ServiceB".to_string()),
+                    stereotypes: Vec::new(),
+                    entity_type: EntityType::Interface,
+                    type_aliases: Vec::new(),
+                    variables: Vec::new(),
+                    methods: Vec::new(),
+                    template_parameters: None,
+                    enum_literals: Vec::new(),
+                    relationships: Vec::new(),
+                    source_location: SourceLocation::new("test_b.puml", 1),
+                },
+            ],
+            free_functions: Vec::new(),
+        }];
+
+        let index = PublicApiIndex::build_index(&diagrams);
+
+        let public_api_ids: BTreeSet<&str> = index.api_ids().map(String::as_str).collect();
+
+        assert_eq!(public_api_ids.len(), 2);
+        assert!(public_api_ids.contains("ServiceA.SampleLibraryAPI"));
+        assert!(public_api_ids.contains("ServiceB.SampleLibraryAPI"));
+    }
 }
diff --git a/validation/core/src/models/component_diagram_models.rs b/validation/core/src/models/component_diagram_models.rs
index 45b932b9..1c305351 100644
--- a/validation/core/src/models/component_diagram_models.rs
+++ b/validation/core/src/models/component_diagram_models.rs
@@ -26,6 +26,9 @@ pub trait LogicComponentExt {
     /// Canonical match key: alias (lowercased) when present, otherwise raw id.
     fn match_key(&self) -> String;
 
+    /// User-facing identifier for diagnostics.
+    fn display_key(&self) -> String;
+
     fn is_component(&self) -> bool;
 
     fn is_unit(&self) -> bool;
@@ -41,6 +44,10 @@ impl LogicComponentExt for LogicComponent {
         self.alias.as_deref().unwrap_or(&self.id).to_lowercase()
     }
 
+    fn display_key(&self) -> String {
+        self.alias.clone().unwrap_or_else(|| self.id.clone())
+    }
+
     fn is_component(&self) -> bool {
         self.stereotype.as_deref() == Some("component")
     }
@@ -79,25 +86,29 @@ impl ComponentDiagramInputs {
 /// Indexed entity key-maps derived from the parsed PlantUML diagram entities.
 ///
 /// Built via [`ComponentDiagramInputs::to_diagram_architecture`].
+/// The keyed sets are Bazel-comparison projections; canonical entity ids stay
+/// on [`ComponentDiagramArchitecture::entities`].
 pub struct ComponentDiagramArchitecture {
-    /// `<<SEooC>>` package entities, keyed with `parent = None`.
+    /// `<<SEooC>>` package entities projected for Bazel comparison, keyed with `parent = None`.
     pub seooc_set: BTreeMap<EntityKey, LogicComponent>,
-    /// `<<component>>` entities, keyed with `parent = Some(..)`.
+    /// `<<component>>` entities projected for Bazel comparison, keyed with `parent = Some(..)`.
     pub comp_set: BTreeMap<EntityKey, LogicComponent>,
+    /// `<<unit>>` entities projected for Bazel comparison, keyed with `parent = Some(..)`.
     pub unit_set: BTreeMap<EntityKey, LogicComponent>,
     /// Full raw entity list, kept for debug output.
     pub entities: Vec<LogicComponent>,
 }
 
 impl ComponentDiagramArchitecture {
-    /// Index `entities` by stereotype and parent alias.
+    /// Index `entities` by stereotype and parent id.
     ///
     /// `<<SEooC>>` go into `seooc_set`;
     /// `<<component>>` go into `comp_set`;
     /// `<<unit>>` go into `unit_set`.
-    /// Duplicates (same [`EntityKey`]) are reported via `result`, except
-    /// benign re-declarations of the exact same entity across multiple
-    /// `static` files (see [`Self::build_set`]), which are merged instead.
+    /// These sets are keyed by names projected for Bazel comparison rather than
+    /// canonical entity ids. Duplicates (same [`EntityKey`]) are reported via
+    /// `result`, except benign re-declarations of the exact same entity across
+    /// multiple `static` files (see [`Self::build_set`]), which are merged instead.
     fn from_entities(entities: &[LogicComponent], result: &mut ValidationResult) -> Self {
         // Index by raw id for parent resolution; PlantUML nesting uses id,
         // not alias.
@@ -121,24 +132,24 @@ impl ComponentDiagramArchitecture {
                     continue;
                 }
                 let kind = entity_kind_name(entity);
-                let alias = entity.match_key();
+                let display_name = entity.display_key();
                 let parent =
-                    entity_parent_alias(entity, &id_index).unwrap_or_else(|| "<none>".to_string());
+                    entity_parent_key(entity, &id_index).unwrap_or_else(|| "<none>".to_string());
                 let ((source_file, source_line), (duplicate_file, duplicate_line)) =
                     ordered_source_locations(&prev.source_location, &entity.source_location);
                 result.add_failure(
                     ErrorBuilder::new(ErrorCategory::Design)
                         .title(format!(
-                            "{kind} \"{alias}\" is defined more than once in the component diagram."
+                            "{kind} \"{display_name}\" is defined more than once in the component diagram."
                         ))
-                        .field(kind, format!("\"{alias}\""))
+                        .field(kind, format!("\"{display_name}\""))
                         .field("parent", &parent)
                         .field("component source file", format!("\"{source_file}\""))
                         .field("component source line", source_line.to_string())
                         .field("duplicate source file", format!("\"{duplicate_file}\""))
                         .field("duplicate source line", duplicate_line.to_string())
                         .fix(format!(
-                            "keep only one {kind} \"{alias}\" under \"{parent}\", or rename one of the duplicate entities"
+                            "keep only one {kind} \"{display_name}\" under \"{parent}\", or rename one of the duplicate entities"
                         ))
                         .build(),
                 );
@@ -183,19 +194,19 @@ impl ComponentDiagramArchitecture {
                     Some(parent) => Some(parent.match_key()),
                     None => {
                         let kind = entity_kind_name(entity);
-                        let alias = entity.match_key();
+                        let display_name = entity.display_key();
                         let (source_file, source_line) = entity.source_location.display();
                         result.add_failure(
                             ErrorBuilder::new(ErrorCategory::Design)
                                 .title(format!(
-                                    "{kind} \"{alias}\" references a parent that is not defined in the component diagram."
+                                    "{kind} \"{display_name}\" references a parent that is not defined in the component diagram."
                                 ))
-                                .field(kind, format!("\"{alias}\""))
+                                .field(kind, format!("\"{display_name}\""))
                                 .field("parent", format!("\"{parent_id}\""))
                                 .field("component source file", format!("\"{source_file}\""))
                                 .field("component source line", source_line.to_string())
                                 .fix(format!(
-                                    "update the parent reference for {kind} \"{alias}\", or add the missing parent entity in the component diagram"
+                                    "update the parent reference for {kind} \"{display_name}\", or add the missing parent entity in the component diagram"
                                 ))
                                 .build(),
                         );
@@ -217,16 +228,16 @@ impl ComponentDiagramArchitecture {
                     continue;
                 }
                 let kind = entity_kind_name(entity);
-                let alias = entity.match_key();
+                let display_name = entity.display_key();
                 let parent = key.1.as_deref().unwrap_or("<none>");
                 let ((source_file, source_line), (duplicate_file, duplicate_line)) =
                     ordered_source_locations(&prev.source_location, &entity.source_location);
                 result.add_failure(
                     ErrorBuilder::new(ErrorCategory::Design)
                         .title(format!(
-                            "{kind} \"{alias}\" is defined more than once in the component diagram."
+                            "{kind} \"{display_name}\" is defined more than once in the component diagram."
                         ))
-                        .field(kind, format!("\"{alias}\""))
+                        .field(kind, format!("\"{display_name}\""))
                         .field("parent", parent)
                         .field("component source file", format!("\"{source_file}\""))
                         .field("component source line", source_line.to_string())
@@ -234,7 +245,7 @@ impl ComponentDiagramArchitecture {
                         .field("duplicate source line", duplicate_line.to_string())
                         .fix(
                             format!(
-                                "keep only one {kind} \"{alias}\" under \"{parent}\", or rename one of the duplicate entities"
+                                "keep only one {kind} \"{display_name}\" under \"{parent}\", or rename one of the duplicate entities"
                             ),
                         )
                         .build(),
@@ -259,14 +270,14 @@ fn entity_kind_name(entity: &LogicComponent) -> &'static str {
     }
 }
 
-fn entity_parent_alias(
+fn entity_parent_key(
     entity: &LogicComponent,
     id_index: &BTreeMap<String, &LogicComponent>,
 ) -> Option<String> {
     entity.parent_id.as_deref().map(|parent_id| {
         id_index
             .get(&parent_id.to_lowercase())
-            .map(|parent| parent.match_key())
+            .map(|parent| parent.display_key())
             .unwrap_or_else(|| parent_id.to_string())
     })
 }
diff --git a/validation/core/src/models/component_diagram_models/component_diagram_merge.rs b/validation/core/src/models/component_diagram_models/component_diagram_merge.rs
index ff6b33a5..3c18eb50 100644
--- a/validation/core/src/models/component_diagram_models/component_diagram_merge.rs
+++ b/validation/core/src/models/component_diagram_models/component_diagram_merge.rs
@@ -67,7 +67,7 @@ pub(super) fn format_conflicting_declaration_error(
     // Order by source location so the message is stable regardless of file order.
     let (first, second) = ordered_declarations(prev, entity);
     let kind = entity_kind_name(first);
-    let alias = first.match_key();
+    let alias = first.display_key();
     let (source_file, source_line) = first.source_location.display();
     let (conflicting_file, conflicting_line) = second.source_location.display();
     ErrorBuilder::new(ErrorCategory::Design)
@@ -135,7 +135,7 @@ pub(super) fn check_single_home_decomposition(
         let parent_alias = entities
             .iter()
             .find(|entity| entity.id.to_lowercase() == *parent_key)
-            .map(LogicComponentExt::match_key)
+            .map(LogicComponentExt::display_key)
             .unwrap_or_else(|| parent_key.clone());
 
         // Report per file so a benign subset re-declaration isn't shown as a duplicate.
@@ -147,7 +147,7 @@ pub(super) fn check_single_home_decomposition(
         for (file, children) in by_file {
             let children_display = children
                 .values()
-                .map(|child| format!("\"{}\"", child.match_key()))
+                .map(|child| format!("\"{}\"", child.display_key()))
                 .collect::<Vec<_>>()
                 .join(", ");
             error = error.field(format!("children in \"{file}\""), children_display);
diff --git a/validation/core/src/models/sequence_diagram_models.rs b/validation/core/src/models/sequence_diagram_models.rs
index aab9a207..91313c27 100644
--- a/validation/core/src/models/sequence_diagram_models.rs
+++ b/validation/core/src/models/sequence_diagram_models.rs
@@ -17,7 +17,8 @@ use std::collections::BTreeMap;
 
 use sequence_logic::{Block, Interaction, Node, SequenceTree, SourceLocation};
 
-use crate::ValidationResult;
+use crate::validators::shared::{display_name_from_source_path, normalize};
+use crate::{ErrorBuilder, ErrorCategory, ValidationResult};
 
 /// Collection of sequence diagrams loaded from one or more FlatBuffer files.
 pub struct SequenceDiagramInputs {
@@ -41,7 +42,7 @@ pub struct ObservedSequenceCall {
 /// Validation-only participant metadata keyed by the participant reference name
 /// used in sequence interactions.
 pub struct SequenceParticipantInfo {
-    pub display_name: String,
+    pub reference_name: String,
     pub source_location: SourceLocation,
 }
 
@@ -49,52 +50,7 @@ impl SequenceParticipantInfo {
     // TODO: Remove this normalization once class diagram identifiers also use
     // `::` namespaces directly instead of `.`.
     pub fn normalize_qualified_name(reference: &str) -> String {
-        reference.replace("::", ".")
-    }
-}
-
-fn strip_supported_html_style_tags(text: &str) -> String {
-    let mut normalized = String::new();
-    let mut index = 0;
-
-    while index < text.len() {
-        let remaining = &text[index..];
-
-        if let Some(tag_len) = supported_html_style_tag_length(remaining) {
-            index += tag_len;
-            continue;
-        }
-
-        let ch = remaining.chars().next().expect("remaining is non-empty");
-        normalized.push(ch);
-        index += ch.len_utf8();
-    }
-
-    normalized
-}
-
-fn supported_html_style_tag_length(text: &str) -> Option<usize> {
-    if !text.starts_with('<') {
-        return None;
-    }
-
-    let end = text.find('>')?;
-    let tag = text[1..end].trim().to_ascii_lowercase();
-
-    let known_tags = [
-        "b", "/b", "i", "/i", "u", "/u", "s", "/s", "w", "/w", "img", "/img", "font", "/font",
-    ];
-    let styled_tags = ["color", "back", "size"];
-
-    let is_known_tag = known_tags.contains(&tag.as_str());
-    let is_styled_tag = styled_tags.iter().any(|styled_tag| {
-        tag == format!("/{styled_tag}") || tag.starts_with(&format!("{styled_tag}:"))
-    });
-
-    if is_known_tag || is_styled_tag {
-        Some(end + 1)
-    } else {
-        None
+        normalize(reference)
     }
 }
 
@@ -114,7 +70,7 @@ pub struct SequenceDiagramIndex {
 impl SequenceDiagramIndex {
     fn from_diagrams(diagrams: &[SequenceTree], result: &mut ValidationResult) -> Self {
         let mut observed_calls = Vec::new();
-        let mut participants = BTreeMap::new();
+        let mut participants: BTreeMap<String, SequenceParticipantInfo> = BTreeMap::new();
 
         for diagram in diagrams {
             for participant in &diagram.participants {
@@ -124,12 +80,47 @@ impl SequenceDiagramIndex {
                     .unwrap_or(&participant.display_name)
                     .to_string();
 
+                let participant_id = normalize(&participant.uid);
+
+                if participant_id.is_empty() {
+                    result.add_failure(missing_participant_uid_error(participant, &reference_name));
+                    continue;
+                }
+
+                if let Some(existing) = participants.get(&participant_id) {
+                    if existing.reference_name != reference_name {
+                        result.add_failure(conflicting_participant_uid_error(
+                            &participant_id,
+                            existing,
+                            participant,
+                            &reference_name,
+                        ));
+                    }
+                } else if let Some((existing_uid, existing)) =
+                    participants.iter().find(|(existing_uid, existing)| {
+                        *existing_uid != &participant_id
+                            && existing.reference_name == reference_name
+                    })
+                {
+                    let (existing_source_file, _) = existing.source_location.display();
+                    let (source_file, _) = participant.source_location.display();
+                    result.add_failure(duplicate_participant_reference_error(
+                        &reference_name,
+                        existing_uid,
+                        existing,
+                        &participant_id,
+                        participant,
+                        &existing_source_file,
+                        &source_file,
+                    ));
+                }
+
                 // Keep the first declaration location when a participant is
                 // declared in more than one input diagram.
                 participants
-                    .entry(reference_name)
+                    .entry(participant_id)
                     .or_insert_with(|| SequenceParticipantInfo {
-                        display_name: strip_supported_html_style_tags(&participant.display_name),
+                        reference_name,
                         source_location: participant.source_location.clone(),
                     });
             }
@@ -150,16 +141,111 @@ impl SequenceDiagramIndex {
     pub fn declared_participants(&self) -> impl Iterator<Item = &str> {
         self.participants.keys().map(String::as_str)
     }
-
-    pub fn participant_info(&self, participant: &str) -> Option<&SequenceParticipantInfo> {
-        self.participants.get(participant)
-    }
-
     pub fn observed_calls(&self) -> &[ObservedSequenceCall] {
         &self.observed_calls
     }
 }
 
+fn conflicting_participant_uid_error(
+    participant_id: &str,
+    existing: &SequenceParticipantInfo,
+    participant: &sequence_logic::SequenceParticipant,
+    reference_name: &str,
+) -> String {
+    let (existing_source_file, existing_source_line) = existing.source_location.display();
+    let (source_file, source_line) = participant.source_location.display();
+
+    ErrorBuilder::new(ErrorCategory::Design)
+        .title(format!(
+            "sequence participant uid \"{participant_id}\" is declared with conflicting reference names"
+        ))
+        .field("participant uid", format!("\"{participant_id}\""))
+        .field(
+            "first participant reference name",
+            format!("\"{}\"", existing.reference_name),
+        )
+        .field(
+            "duplicate participant reference name",
+            format!("\"{reference_name}\""),
+        )
+        .field(
+            "first sequence source file",
+            format!("\"{existing_source_file}\""),
+        )
+        .field("first sequence source line", existing_source_line.to_string())
+        .field("duplicate sequence source file", format!("\"{source_file}\""))
+        .field("duplicate sequence source line", source_line.to_string())
+        .fix("use one reference name consistently for the same sequence participant uid")
+        .build()
+}
+
+fn duplicate_participant_reference_error(
+    reference_name: &str,
+    existing_uid: &str,
+    existing: &SequenceParticipantInfo,
+    participant_uid: &str,
+    participant: &sequence_logic::SequenceParticipant,
+    existing_source_file: &str,
+    source_file: &str,
+) -> String {
+    let (_, existing_source_line) = existing.source_location.display();
+    let (_, source_line) = participant.source_location.display();
+    let existing_uid = display_name_from_source_path(existing_uid, existing_source_file, 2);
+    let participant_uid = display_name_from_source_path(participant_uid, source_file, 2);
+
+    ErrorBuilder::new(ErrorCategory::Design)
+        .title(format!(
+            "sequence participant reference name \"{reference_name}\" refers to multiple uids"
+        ))
+        .field(
+            "participant reference name",
+            format!("\"{reference_name}\""),
+        )
+        .field("first participant uid", format!("\"{existing_uid}\""))
+        .field(
+            "duplicate participant uid",
+            format!("\"{participant_uid}\""),
+        )
+        .field(
+            "first sequence source file",
+            format!("\"{existing_source_file}\""),
+        )
+        .field(
+            "first sequence source line",
+            existing_source_line.to_string(),
+        )
+        .field(
+            "duplicate sequence source file",
+            format!("\"{source_file}\""),
+        )
+        .field("duplicate sequence source line", source_line.to_string())
+        .fix("rename one participant alias or use a unique participant reference name")
+        .build()
+}
+
+fn missing_participant_uid_error(
+    participant: &sequence_logic::SequenceParticipant,
+    reference_name: &str,
+) -> String {
+    let (source_file, source_line) = participant.source_location.display();
+
+    ErrorBuilder::new(ErrorCategory::Design)
+        .title(format!(
+            "sequence participant \"{reference_name}\" is missing the uid required for validation"
+        ))
+        .field("participant reference name", format!("\"{reference_name}\""))
+        .field(
+            "participant display name",
+            format!("\"{}\"", participant.display_name),
+        )
+        .field("sequence source file", format!("\"{source_file}\""))
+        .field("sequence source line", source_line.to_string())
+        .fix(
+            "set the participant uid to the canonical component or class identifier used by validation",
+        )
+        .build()
+}
+
 fn collect_block_data(
     block: &Block,
     observed_calls: &mut Vec<ObservedSequenceCall>,
@@ -222,7 +308,7 @@ fn observe_interaction(interaction: &Interaction) -> ObservedSequenceCall {
 mod tests {
     use super::*;
     use crate::validators::fixtures::dummy_source_location;
-    use sequence_logic::{Branch, BranchCase, Interaction};
+    use sequence_logic::{Branch, BranchCase, Interaction, ParticipantType, SequenceParticipant};
 
     fn interaction(caller: Option<&str>, callee: Option<&str>, method: &str) -> Node {
         Node::Interaction(Interaction {
@@ -314,4 +400,30 @@ mod tests {
         assert_eq!(index.observed_calls()[0].caller, "unit_1");
         assert_eq!(index.observed_calls()[0].callee, EXTERNAL_ENDPOINT_NAME);
     }
+
+    #[test]
+    fn sequence_index_reports_missing_participant_uid_without_fallback_indexing() {
+        let inputs = SequenceDiagramInputs {
+            diagrams: vec![SequenceTree {
+                name: Some("seq".to_string()),
+                participants: vec![SequenceParticipant {
+                    display_name: ":Process/nara::com user".to_string(),
+                    alias: Some("help".to_string()),
+                    uid: String::new(),
+                    participant_type: ParticipantType::Participant,
+                    source_location: dummy_source_location(),
+                    stereotype: None,
+                }],
+                root: Block { items: Vec::new() },
+            }],
+        };
+
+        let mut result = ValidationResult::default();
+        let index = inputs.to_sequence_diagram_index(&mut result);
+
+        assert_eq!(index.participants().len(), 0);
+        assert_eq!(result.failures.len(), 1);
+        assert!(result.failures[0].contains("missing the uid required for validation"));
+        assert!(result.failures[0].contains("\"help\""));
+    }
 }
diff --git a/validation/core/src/models/shared.rs b/validation/core/src/models/shared.rs
index 412111a2..d1e4e36c 100644
--- a/validation/core/src/models/shared.rs
+++ b/validation/core/src/models/shared.rs
@@ -15,9 +15,10 @@
 
 use crate::{ErrorBuilder, ErrorCategory};
 
-/// Composite key: `(canonical_alias, parent_alias)`. `parent_alias` is `None`
-/// for top-level entities. Using the parent as part of the key means two
-/// identically-named entities under different parents are treated as distinct.
+/// Composite comparison key: `(name, parent_name)`. `parent_name` is `None`
+/// for top-level entities. The names are normalized projections used to compare
+/// Bazel targets with component-diagram entities. Including the parent means
+/// entities with the same name under different parents are distinct.
 pub type EntityKey = (String, Option<String>);
 
 /// Extract the target name from a Bazel label like `@//path/to/package:target`
diff --git a/validation/core/src/readers/class_diagram_reader.rs b/validation/core/src/readers/class_diagram_reader.rs
index d99faaec..d83dfe76 100644
--- a/validation/core/src/readers/class_diagram_reader.rs
+++ b/validation/core/src/readers/class_diagram_reader.rs
@@ -19,6 +19,7 @@ use class_fbs::class_metamodel as fb_class;
 
 use crate::models::ClassDiagramInputs;
 use crate::readers::{to_source_location, Reader};
+use crate::validators::shared::normalize;
 use class_diagram::{
     ClassDiagram, EntityType, EnumLiteral, FunctionArgument, MemberVariable, Method,
     MethodModifier, RelationType, Relationship, SimpleEntity, TemplateParameter, TypeAlias,
@@ -27,6 +28,65 @@ use class_diagram::{
 
 pub struct ClassDiagramReader;
 
+fn canonical_reference_name(text: &str) -> String {
+    normalize(text.trim())
+}
+
+fn canonical_optional_reference_name(value: Option<&str>) -> Option<String> {
+    value.map(canonical_reference_name)
+}
+
+fn canonical_template_parameters(
+    values: Option<Vec<TemplateParameter>>,
+) -> Option<Vec<TemplateParameter>> {
+    values.map(|parameters| {
+        parameters
+            .into_iter()
+            .map(canonical_template_parameter)
+            .collect()
+    })
+}
+
+fn canonical_function_arguments(values: Vec<FunctionArgument>) -> Vec<FunctionArgument> {
+    values
+        .into_iter()
+        .map(|parameter| FunctionArgument {
+            param_type: parameter
+                .param_type
+                .as_deref()
+                .map(canonical_reference_name),
+            ..parameter
+        })
+        .collect()
+}
+
+fn canonical_template_parameter(parameter: TemplateParameter) -> TemplateParameter {
+    match parameter {
+        TemplateParameter::Type { name, is_pack } => TemplateParameter::Type { name, is_pack },
+        TemplateParameter::NonType {
+            name,
+            value_type,
+            is_pack,
+        } => TemplateParameter::NonType {
+            name,
+            value_type: canonical_reference_name(&value_type),
+            is_pack,
+        },
+        TemplateParameter::Template {
+            name,
+            parameters,
+            is_pack,
+        } => TemplateParameter::Template {
+            name,
+            parameters: parameters
+                .into_iter()
+                .map(canonical_template_parameter)
+                .collect(),
+            is_pack,
+        },
+    }
+}
+
 fn read_template_parameters(
     values: Option<
         flatbuffers::Vector<'_, flatbuffers::ForwardsUOffset<fb_class::TemplateParameter<'_>>>,
@@ -88,7 +148,7 @@ fn read_type_aliases(entity: fb_class::SimpleEntity<'_>) -> Vec<TypeAlias> {
                 .iter()
                 .map(|value| TypeAlias {
                     alias: value.alias().to_string(),
-                    original_type: value.original_type().to_string(),
+                    original_type: canonical_reference_name(value.original_type()),
                     source_location: to_source_location(
                         value.source_location().file(),
                         value.source_location().line(),
@@ -111,7 +171,7 @@ fn read_variables(
                 .map(|value| {
                     Ok(MemberVariable {
                         name: value.name().to_string(),
-                        data_type: value.data_type().map(|s| s.to_string()),
+                        data_type: canonical_optional_reference_name(value.data_type()),
                         visibility: map_visibility(
                             value.visibility(),
                             &format!("{path}:entity:{}:variable:{}", entity.id(), value.name()),
@@ -171,13 +231,13 @@ fn read_method(
 
     Ok(Method {
         name: method.name().to_string(),
-        return_type: method.return_type().map(|s| s.to_string()),
+        return_type: canonical_optional_reference_name(method.return_type()),
         visibility: map_visibility(
             method.visibility(),
             &format!("{path}:entity:{}:method:{}", entity.id(), method.name()),
         )?,
-        parameters,
-        template_parameters,
+        parameters: canonical_function_arguments(parameters),
+        template_parameters: canonical_template_parameters(template_parameters),
         modifiers,
         source_location: to_source_location(
             method.source_location().file(),
@@ -238,9 +298,9 @@ fn read_entity_relationships(
 
 fn read_entity(entity: fb_class::SimpleEntity<'_>, path: &str) -> Result<SimpleEntity, String> {
     Ok(SimpleEntity {
-        id: entity.id().to_string(),
+        id: canonical_reference_name(entity.id()),
         name: entity.name().to_string(),
-        enclosing_namespace_id: entity.enclosing_namespace_id().map(|s| s.to_string()),
+        enclosing_namespace_id: canonical_optional_reference_name(entity.enclosing_namespace_id()),
         stereotypes: entity
             .stereotypes()
             .map(|values| values.iter().map(|value| value.to_string()).collect())
@@ -252,10 +312,10 @@ fn read_entity(entity: fb_class::SimpleEntity<'_>, path: &str) -> Result<SimpleE
         type_aliases: read_type_aliases(entity),
         variables: read_variables(entity, path)?,
         methods: read_methods(entity, path)?,
-        template_parameters: read_template_parameters(
+        template_parameters: canonical_template_parameters(read_template_parameters(
             entity.template_parameters(),
             &format!("{path}:entity:{}", entity.id()),
-        )?,
+        )?),
         enum_literals: read_enum_literals(entity),
         relationships: read_entity_relationships(entity, path)?,
         source_location: to_source_location(
@@ -285,8 +345,8 @@ fn read_relationship(
     context: &str,
 ) -> Result<Relationship, String> {
     Ok(Relationship {
-        source: rel.source().to_string(),
-        target: rel.target().to_string(),
+        source: canonical_reference_name(rel.source()),
+        target: canonical_reference_name(rel.target()),
         relation_type: map_relation_type(rel.relation_type(), context)?,
         source_multiplicity: rel.source_multiplicity().map(|s| s.to_string()),
         target_multiplicity: rel.target_multiplicity().map(|s| s.to_string()),
@@ -384,3 +444,47 @@ fn map_method_modifier(
         _ => Err(unsupported_enum(context, "method_modifier", value)),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::{canonical_reference_name, canonical_template_parameter};
+    use class_diagram::TemplateParameter;
+
+    #[test]
+    fn canonical_reference_name_uses_dot_namespaces() {
+        assert_eq!(
+            canonical_reference_name("vehicle::Engine"),
+            "vehicle.Engine"
+        );
+        assert_eq!(
+            canonical_reference_name(" validation.core.Engine "),
+            "validation.core.Engine"
+        );
+    }
+
+    #[test]
+    fn canonical_template_parameter_normalizes_non_type_value_types_recursively() {
+        let parameter = TemplateParameter::Template {
+            name: "Factory".to_string(),
+            parameters: vec![TemplateParameter::NonType {
+                name: "Value".to_string(),
+                value_type: "score::cpp::Span".to_string(),
+                is_pack: false,
+            }],
+            is_pack: false,
+        };
+
+        assert_eq!(
+            canonical_template_parameter(parameter),
+            TemplateParameter::Template {
+                name: "Factory".to_string(),
+                parameters: vec![TemplateParameter::NonType {
+                    name: "Value".to_string(),
+                    value_type: "score.cpp.Span".to_string(),
+                    is_pack: false,
+                }],
+                is_pack: false,
+            }
+        );
+    }
+}
diff --git a/validation/core/src/readers/sequence_diagram_reader.rs b/validation/core/src/readers/sequence_diagram_reader.rs
index c2360578..932df440 100644
--- a/validation/core/src/readers/sequence_diagram_reader.rs
+++ b/validation/core/src/readers/sequence_diagram_reader.rs
@@ -258,6 +258,7 @@ fn read_participant(
     Ok(SequenceParticipant {
         display_name: participant.display_name().to_string(),
         alias: participant.alias().map(|s| s.to_string()),
+        uid: participant.uid().map(|s| s.to_string()).unwrap_or_default(),
         participant_type: map_participant_type(participant.participant_type())
             .map_err(|err| format!("{participant_path}: {err}"))?,
         source_location: to_source_location(
diff --git a/validation/core/src/validators/class_design_implementation_validator.rs b/validation/core/src/validators/class_design_implementation_validator.rs
index b43b27fd..cc689e61 100644
--- a/validation/core/src/validators/class_design_implementation_validator.rs
+++ b/validation/core/src/validators/class_design_implementation_validator.rs
@@ -14,7 +14,10 @@
 //! Class implementation validation: compare unit design class diagrams with
 //! C++ implementation produced by the C++ parser.
 
-use super::shared::best_string_suggestion;
+use super::shared::{
+    best_string_suggestion, display_entity_name, display_reference_name, display_relationship_name,
+    normalize,
+};
 use crate::models::ClassEntityIndex;
 use crate::results::{ErrorBuilder, ErrorCategory};
 use crate::ValidationResult;
@@ -64,16 +67,13 @@ impl ClassDesignImplementationValidator {
     ) {
         for design_entity in design_classes.entities() {
             let normalized_design_id = normalize_reference_name(&design_entity.id);
-            let Some(implementation_entity) = implementation_classes
-                .find_by_id(&design_entity.id)
-                .or_else(|| implementation_classes.find_by_id(&normalized_design_id))
-            else {
-                let suggested_class = best_string_suggestion(
-                    &design_entity.id,
-                    implementation_classes
-                        .entities()
-                        .map(|entity| entity.id.as_str()),
-                );
+            let Some(implementation_entity) = find_implementation_entity(
+                implementation_classes,
+                &design_entity.id,
+                &normalized_design_id,
+            ) else {
+                let suggested_class =
+                    best_implementation_class_suggestion(&design_entity.id, implementation_classes);
                 self.result.add_failure(Self::format_missing_class(
                     design_entity,
                     suggested_class.as_deref(),
@@ -150,8 +150,8 @@ impl ClassDesignImplementationValidator {
                         design_alias.alias.as_str()
                     ),
                     FieldReferenceStyle::Verbatim,
-                    &design_alias.original_type,
-                    &implementation_alias.original_type,
+                    &normalize_type_name(&design_alias.original_type),
+                    &normalize_type_name(&implementation_alias.original_type),
                 )),
                 None => self.result.add_failure(Self::format_missing_member(
                     design_entity,
@@ -453,11 +453,14 @@ impl ClassDesignImplementationValidator {
         design_entity: &SimpleEntity,
         implementation_entity: &SimpleEntity,
     ) {
-        let implementation_relationships = relationship_map(implementation_entity);
         for design_relationship in &design_entity.relationships {
-            let key = relationship_key(design_relationship);
-            let display_name = relationship_display_name(design_relationship);
-            match implementation_relationships.get(key.as_str()) {
+            let display_name = display_relationship_name(design_relationship);
+            match implementation_entity
+                .relationships
+                .iter()
+                .find(|implementation_relationship| {
+                    relationships_share_endpoints(design_relationship, implementation_relationship)
+                }) {
                 Some(implementation_relationship)
                     if design_relationship.relation_type
                         == implementation_relationship.relation_type => {}
@@ -468,22 +471,22 @@ impl ClassDesignImplementationValidator {
                         "relationship type",
                         FieldReferenceStyle::Quoted,
                         &display_name,
-                        &relationship_display_name(implementation_relationship),
+                        &display_relationship_name(implementation_relationship),
                     ))
                 }
                 None => {
                     let implementation_relationship_names = implementation_entity
                         .relationships
                         .iter()
-                        .map(relationship_display_name)
+                        .map(display_relationship_name)
                         .collect::<Vec<_>>();
                     self.result.add_failure(Self::format_missing_member(
                         design_entity,
                         "relationship",
                         &display_name,
-                        best_string_suggestion(
-                            &display_name,
-                            implementation_relationship_names.iter().map(String::as_str),
+                        best_relationship_suggestion(
+                            design_relationship,
+                            &implementation_relationship_names,
                         )
                         .as_deref(),
                     ))
@@ -493,21 +496,23 @@ impl ClassDesignImplementationValidator {
     }
 
     fn format_missing_class(entity: &SimpleEntity, suggested_class: Option<&str>) -> String {
+        let display_name = display_entity_name(entity);
+
         let error = ErrorBuilder::new(ErrorCategory::Class)
             .title(format!(
                 "class \"{}\" from the unit design not found in the C++ class implementation",
-                entity.id
+                display_name
             ))
-            .field("class", format!("\"{}\"", entity.id))
+            .field("class", format!("\"{}\"", display_name))
             .field("design source file", format!("\"{}\"", design_source_file(entity)))
             .field("design source line", design_source_line(entity).to_string())
             .fix(format!(
                 "add implementation class \"{}\" in the C++ class implementation, or remove it from the unit design",
-                entity.id
+                display_name
             ));
 
         let error = if let Some(suggested_class) = suggested_class {
-            error.suggest(&entity.id, Some("class"), suggested_class)
+            error.suggest(display_name, Some("class"), suggested_class)
         } else {
             error
         };
@@ -521,12 +526,14 @@ impl ClassDesignImplementationValidator {
         member_name: &str,
         suggested_member: Option<&str>,
     ) -> String {
+        let display_entity = display_entity_name(design_entity);
+
         let error = ErrorBuilder::new(ErrorCategory::Member)
             .title(format!(
                 "{member_type} \"{member_name}\" from entity \"{}\" in the unit design not found in the C++ class implementation",
-                design_entity.id
+                display_entity
             ))
-            .field("entity", format!("\"{}\"", design_entity.id))
+            .field("entity", format!("\"{}\"", display_entity))
             .field("member", format!("{member_type} \"{member_name}\""))
             .field(
                 "design source file",
@@ -535,7 +542,7 @@ impl ClassDesignImplementationValidator {
             .field("design source line", design_source_line(design_entity).to_string())
             .fix(format!(
                 "add {member_type} \"{member_name}\" to entity \"{}\" in the C++ class implementation, or remove it from the unit design",
-                design_entity.id
+                display_entity
             ));
 
         let error = if let Some(suggested_member) = suggested_member {
@@ -556,13 +563,14 @@ impl ClassDesignImplementationValidator {
         implementation_value: &str,
     ) -> String {
         let field_reference = format_field_reference(field, field_reference_style);
+        let display_entity = display_entity_name(design_entity);
 
         ErrorBuilder::new(ErrorCategory::Implementation)
             .title(format!(
                 "field {field_reference} on entity \"{}\" differs between the unit design and the C++ class implementation",
-                design_entity.id,
+                display_entity,
             ))
-            .field("entity", format!("\"{}\"", design_entity.id))
+            .field("entity", format!("\"{}\"", display_entity))
             .field("field", field)
             .field("design value", design_value)
             .field(
@@ -581,12 +589,62 @@ impl ClassDesignImplementationValidator {
             )
             .fix(format!(
                 "make {field_reference} in entity \"{}\" consistent between the unit design and the C++ class implementation",
-                design_entity.id
+                display_entity
             ))
             .build()
     }
 }
 
+fn find_implementation_entity<'a>(
+    implementation_classes: &'a ClassEntityIndex,
+    design_id: &str,
+    normalized_design_id: &str,
+) -> Option<&'a SimpleEntity> {
+    implementation_classes
+        .find_by_id(design_id)
+        .or_else(|| implementation_classes.find_by_id(normalized_design_id))
+        .or_else(|| find_unique_normalized_id_match(implementation_classes, normalized_design_id))
+}
+
+fn find_unique_normalized_id_match<'a>(
+    classes: &'a ClassEntityIndex,
+    normalized_id: &str,
+) -> Option<&'a SimpleEntity> {
+    let mut matches = classes
+        .entities()
+        .filter(|entity| normalize_reference_name(&entity.id) == normalized_id);
+
+    let first_match = matches.next()?;
+    if matches.next().is_some() {
+        return None;
+    }
+
+    Some(first_match)
+}
+
+fn best_implementation_class_suggestion(
+    design_id: &str,
+    implementation_classes: &ClassEntityIndex,
+) -> Option<String> {
+    let design_name = display_reference_name(design_id);
+    best_string_suggestion(
+        design_name,
+        implementation_classes
+            .entities()
+            .map(|entity| display_reference_name(&entity.id)),
+    )
+}
+
+fn best_relationship_suggestion(
+    design_relationship: &Relationship,
+    implementation_relationship_names: &[String],
+) -> Option<String> {
+    best_string_suggestion(
+        &display_relationship_name(design_relationship),
+        implementation_relationship_names.iter().map(String::as_str),
+    )
+}
+
 fn format_field_reference(field: &str, style: FieldReferenceStyle) -> String {
     match style {
         FieldReferenceStyle::Quoted => format!("\"{field}\""),
@@ -920,15 +978,14 @@ fn normalize_type_name(type_name: &str) -> String {
         &type_name
             .trim()
             .trim_start_matches("::")
-            .replace("std::", "")
             .replace(" *", "*")
             .replace(" &", "&"),
     )
+    .replace("std.", "")
 }
 
 fn normalize_reference_name(reference: &str) -> String {
-    // TODO: Remove this workaround once class diagram and implementation parser UIDs use the same namespace separator.
-    reference.trim().replace('.', "::")
+    normalize(reference)
 }
 
 fn enum_literal_map(entity: &SimpleEntity) -> BTreeMap<&str, &EnumLiteral> {
@@ -951,27 +1008,31 @@ fn enum_literal_value(literal: &EnumLiteral) -> String {
     }
 }
 
-fn relationship_map(entity: &SimpleEntity) -> BTreeMap<String, &Relationship> {
-    entity
-        .relationships
-        .iter()
-        .map(|relationship| (relationship_key(relationship), relationship))
-        .collect()
+fn relationships_share_endpoints(
+    design_relationship: &Relationship,
+    implementation_relationship: &Relationship,
+) -> bool {
+    references_match(
+        &design_relationship.source,
+        &implementation_relationship.source,
+    ) && references_match(
+        &design_relationship.target,
+        &implementation_relationship.target,
+    )
 }
 
-fn relationship_key(relationship: &Relationship) -> String {
-    format!(
-        "{} -> {}",
-        normalize_reference_name(&relationship.source),
-        normalize_reference_name(&relationship.target)
-    )
+fn references_match(left: &str, right: &str) -> bool {
+    let normalized_left = normalize_reference_name(left);
+    let normalized_right = normalize_reference_name(right);
+
+    normalized_left == normalized_right
 }
 
-fn relationship_display_name(relationship: &Relationship) -> String {
+#[cfg(test)]
+fn relationship_key(relationship: &Relationship) -> String {
     format!(
-        "{} -> {:?} -> {}",
+        "{} -> {}",
         normalize_reference_name(&relationship.source),
-        relationship.relation_type,
         normalize_reference_name(&relationship.target)
     )
 }
@@ -1115,10 +1176,7 @@ mod tests {
             parameter("args", "vehicle.Payload", true),
         ];
 
-        assert_eq!(
-            method_key(&method),
-            "dispatch(uint8_t, vehicle::Payload...)"
-        );
+        assert_eq!(method_key(&method), "dispatch(uint8_t, vehicle.Payload...)");
     }
 
     #[test]
@@ -1168,21 +1226,18 @@ mod tests {
 
         assert_eq!(
             relationship_key(&relationship),
-            "vehicle::Engine -> vehicle::Manufacturer"
+            "vehicle.Engine -> vehicle.Manufacturer"
         );
         assert_eq!(
-            relationship_display_name(&relationship),
-            "vehicle::Engine -> Composition -> vehicle::Manufacturer"
+            display_relationship_name(&relationship),
+            "Engine -> Composition -> Manufacturer"
         );
     }
 
     #[test]
     fn type_name_normalization_ignores_pointer_and_reference_spacing() {
         assert_eq!(normalize_type_name("std::uint8_t *"), "uint8_t*");
-        assert_eq!(
-            normalize_type_name("vehicle.Payload &"),
-            "vehicle::Payload&"
-        );
+        assert_eq!(normalize_type_name("vehicle.Payload &"), "vehicle.Payload&");
     }
 
     #[test]
@@ -1190,8 +1245,67 @@ mod tests {
         assert_eq!(normalize_type_name("::std::uint8_t"), "uint8_t");
         assert_eq!(
             normalize_type_name(" ::vehicle::Payload "),
-            "vehicle::Payload"
+            "vehicle.Payload"
+        );
+    }
+
+    #[test]
+    fn implementation_entity_match_rejects_root_anchored_design_id_suffix() {
+        let implementation_classes = index(vec![entity_in_namespace(
+            "vehicle::Engine",
+            Some("vehicle"),
+            vec![],
+        )]);
+
+        let matched = find_implementation_entity(
+            &implementation_classes,
+            "validation.core.integration_test.case.vehicle.Engine",
+            "validation.core.integration_test.case.vehicle.Engine",
+        );
+
+        assert!(matched.is_none());
+    }
+
+    #[test]
+    fn implementation_class_suggestion_uses_leaf_name_for_root_anchored_design_id() {
+        let implementation_classes = index(vec![entity("ControlPanl", vec![])]);
+
+        let suggested = best_implementation_class_suggestion(
+            "validation.core.integration_test.case.ControlPanel",
+            &implementation_classes,
+        );
+
+        assert_eq!(suggested, Some("ControlPanl".to_string()));
+    }
+
+    #[test]
+    fn relationship_endpoint_match_rejects_root_anchored_design_id_suffix() {
+        let design = relationship(
+            "validation.core.integration_test.case.vehicle.Engine",
+            "validation.core.integration_test.case.vehicle.Manufacturer",
+            RelationType::Composition,
+        );
+        let implementation = relationship(
+            "vehicle::Engine",
+            "vehicle::Manufacturer",
+            RelationType::Composition,
         );
+
+        assert!(!relationships_share_endpoints(&design, &implementation));
+    }
+
+    #[test]
+    fn relationship_suggestion_uses_leaf_names_for_root_anchored_design_ids() {
+        let design = relationship(
+            "validation.core.integration_test.case.Car",
+            "validation.core.integration_test.case.Wheel",
+            RelationType::Composition,
+        );
+        let suggestions = vec!["Car -> Composition -> Whell".to_string()];
+
+        let suggested = best_relationship_suggestion(&design, &suggestions);
+
+        assert_eq!(suggested, Some("Car -> Composition -> Whell".to_string()));
     }
 
     #[test]
diff --git a/validation/core/src/validators/class_design_sequence_validator.rs b/validation/core/src/validators/class_design_sequence_validator.rs
index 3d63f7dc..13eb4881 100644
--- a/validation/core/src/validators/class_design_sequence_validator.rs
+++ b/validation/core/src/validators/class_design_sequence_validator.rs
@@ -15,7 +15,10 @@
 
 use std::collections::BTreeSet;
 
-use super::shared::{best_string_suggestion, extract_method_name, format_sequence_call};
+use super::shared::{
+    best_string_suggestion, display_entity_name, display_name_from_source_path_in_context,
+    display_reference_name, extract_method_name, format_sequence_call,
+};
 use crate::models::{
     ClassEntityIndex, ObservedSequenceCall, SequenceDiagramIndex, SequenceParticipantInfo,
 };
@@ -79,24 +82,16 @@ impl<'a> ClassDesignSequenceValidator<'a> {
     ) {
         let (source_file, source_line) = participant_info.source_location.display();
 
-        if let Some(display_issue) = unsupported_participant_display_form(participant_info) {
-            self.report_unsupported_participant_display_name(
-                participant,
-                participant_info,
-                &source_file,
-                source_line,
-                display_issue,
-            );
+        if !looks_like_class_identifier(participant) {
+            self.result
+                .add_failure(self.invalid_participant_identifier_failure(
+                    participant,
+                    &source_file,
+                    source_line,
+                ));
             return;
         }
 
-        self.log_ignored_special_display_suffix(
-            participant,
-            participant_info,
-            &source_file,
-            source_line,
-        );
-
         match self.resolve_participant_class(participant) {
             ParticipantResolution::Matched(_) => {}
             ParticipantResolution::Missing => {
@@ -107,83 +102,78 @@ impl<'a> ClassDesignSequenceValidator<'a> {
                     source_line,
                 ))
             }
-            ParticipantResolution::Ambiguous(matches) => {
-                self.result.add_failure(self.ambiguous_participant_failure(
-                    participant,
-                    &source_file,
-                    source_line,
-                    &matches,
-                ))
-            }
         }
     }
 
-    fn log_ignored_special_display_suffix(
+    fn invalid_participant_identifier_failure(
         &self,
         participant: &str,
-        participant_info: &SequenceParticipantInfo,
         source_file: &str,
         source_line: u32,
-    ) {
-        if let Some(ignored_suffix) = ignored_special_display_suffix(participant_info) {
-            log::warn!(
-                "sequence participant \"{}\" ignores trailing special display text \"{}\" at {}:{}; it is not treated as namespace or class matching data",
-                participant,
-                ignored_suffix,
-                source_file,
-                source_line,
-            );
-        }
+    ) -> String {
+        let display_participant =
+            display_sequence_participant_name_from_source(participant, source_file);
+
+        ErrorBuilder::new(ErrorCategory::Class)
+            .title(format!(
+                "sequence participant \"{display_participant}\" does not provide a valid class identifier for class-design validation"
+            ))
+            .field("participant", format!("\"{participant}\""))
+            .field("sequence source file", format!("\"{source_file}\""))
+            .field("sequence source line", source_line.to_string())
+            .fix(format!(
+                "set the participant uid to a class id such as \"{display_participant}\", or change the participant declaration to use a valid class identifier"
+            ))
+            .build()
     }
 
     fn missing_participant_failure(
         &self,
         participant: &str,
-        participant_info: &SequenceParticipantInfo,
+        _participant_info: &SequenceParticipantInfo,
         source_file: &str,
         source_line: u32,
     ) -> String {
+        let display_participant =
+            display_sequence_participant_name_from_source(participant, source_file);
+        let suggested_class = self.best_participant_class_suggestion(participant);
+        let display_suggested_class = suggested_class.map(display_suggested_class_name);
+        let missing_class_name = suggested_class
+            .filter(|entity| self.should_use_suggested_class_in_fix(&display_participant, entity))
+            .map(display_suggested_class_name)
+            .unwrap_or_else(|| display_participant.clone());
         let error = ErrorBuilder::new(ErrorCategory::Class)
             .title(format!(
-                "sequence participant \"{participant}\" has no matching class in the class diagram"
+                "sequence participant \"{display_participant}\" has no matching class in the class diagram"
             ))
-            .field("participant", format!("\"{participant}\""))
+            .field("participant", format!("\"{display_participant}\""))
             .field("sequence source file", format!("\"{source_file}\""))
             .field("sequence source line", source_line.to_string())
             .fix(format!(
-                "add class \"{participant}\" to the class diagram, or remove the participant from the sequence diagram"
+                "add class \"{missing_class_name}\" to the class diagram, or remove the participant from the sequence diagram"
             ));
 
-        if let Some(suggested_class) = self
-            .best_participant_class_suggestion(participant, participant_info)
-            .as_deref()
-        {
-            error.suggest(participant, Some("class"), suggested_class)
+        if let Some(display_suggested_class) = display_suggested_class.as_deref() {
+            error.suggest(&display_participant, Some("class"), display_suggested_class)
         } else {
             error
         }
         .build()
     }
 
-    fn ambiguous_participant_failure(
+    fn should_use_suggested_class_in_fix(
         &self,
-        participant: &str,
-        source_file: &str,
-        source_line: u32,
-        matches: &BTreeSet<String>,
-    ) -> String {
-        ErrorBuilder::new(ErrorCategory::Class)
-            .title(format!(
-                "sequence participant \"{participant}\" matches multiple classes in the class diagram"
-            ))
-            .field("participant", format!("\"{participant}\""))
-            .field("matching classes", format_name_set(matches))
-            .field("sequence source file", format!("\"{source_file}\""))
-            .field("sequence source line", source_line.to_string())
-            .fix(format!(
-                "rename participant \"{participant}\" in the sequence diagram to a unique class id, or rename one of the matching classes in the class diagram"
-            ))
-            .build()
+        display_participant: &str,
+        suggested_class: &class_diagram::SimpleEntity,
+    ) -> bool {
+        suggested_class.name == display_participant
+            && self
+                .design_classes
+                .entities()
+                .filter(|entity| entity.name == display_participant)
+                .take(2)
+                .count()
+                == 1
     }
 
     fn check_message_operation_consistency(&mut self) {
@@ -229,8 +219,12 @@ impl<'a> ClassDesignSequenceValidator<'a> {
         method_name: &str,
         method_lookup: MethodLookupResult,
     ) -> String {
-        let sequence_call =
-            format_sequence_call(&observed_call.caller, &observed_call.callee, method_name);
+        let sequence_call = format_sequence_call(
+            display_reference_name(&observed_call.caller),
+            display_reference_name(&observed_call.callee),
+            method_name,
+        );
+        let target_class = display_entity_name(callee_class);
         let (source_file, source_line) = observed_call.source_location.display();
 
         match method_lookup {
@@ -240,30 +234,30 @@ impl<'a> ClassDesignSequenceValidator<'a> {
             MethodLookupResult::FoundPrivateInherited => ErrorBuilder::new(ErrorCategory::Method)
                 .title(format!(
                     "sequence function \"{method_name}\" from sequence call {sequence_call} exists only as a private inherited method on target class \"{}\" in the class diagram",
-                    callee_class.id,
+                    target_class,
                 ))
                 .field("sequence call", sequence_call)
-                .field("target class", format!("\"{}\"", callee_class.id))
+                .field("target class", format!("\"{}\"", target_class))
                 .field("sequence source file", format!("\"{source_file}\""))
                 .field("sequence source line", source_line.to_string())
                 .fix(format!(
                     "consider changing method \"{method_name}\" to public or protected on an inherited type of class \"{}\", add an accessible wrapper on that class, or change or remove that sequence call",
-                    callee_class.id,
+                    target_class,
                 ))
                 .build(),
             MethodLookupResult::NotFound => {
                 let error = ErrorBuilder::new(ErrorCategory::Method)
                 .title(format!(
                     "sequence function \"{method_name}\" from sequence call {sequence_call} not found on target class \"{}\" or its accessible inherited types in the class diagram",
-                    callee_class.id,
+                    target_class,
                 ))
                 .field("sequence call", sequence_call)
-                .field("target class", format!("\"{}\"", callee_class.id))
+                .field("target class", format!("\"{}\"", target_class))
                 .field("sequence source file", format!("\"{source_file}\""))
                 .field("sequence source line", source_line.to_string())
                 .fix(format!(
                     "add method \"{method_name}\" to class \"{}\" or one of its accessible inherited types in the class diagram, or change or remove that sequence call",
-                    callee_class.id,
+                    target_class,
                 ));
 
                 if let Some(suggested_method) = self
@@ -282,19 +276,19 @@ impl<'a> ClassDesignSequenceValidator<'a> {
     fn best_participant_class_suggestion(
         &self,
         participant: &str,
-        participant_info: &SequenceParticipantInfo,
-    ) -> Option<String> {
+    ) -> Option<&'a class_diagram::SimpleEntity> {
         let class_candidates: BTreeSet<String> = self
             .design_classes
             .entities()
-            .flat_map(|entity| [entity.id.clone(), entity.name.clone()])
+            .map(|entity| entity.id.clone())
             .filter(|candidate| !candidate.is_empty())
             .collect();
 
-        participant_suggestion_queries(participant, participant_info)
+        participant_suggestion_queries(participant)
             .into_iter()
             .find_map(|query| {
                 best_string_suggestion(&query, class_candidates.iter().map(String::as_str))
+                    .and_then(|suggested_id| self.design_classes.find_by_id(&suggested_id))
             })
     }
 
@@ -315,21 +309,7 @@ impl<'a> ClassDesignSequenceValidator<'a> {
             return resolution;
         }
 
-        if let Some(participant_info) = self.sequence_diagram.participant_info(participant) {
-            if let Some(resolution) = self.resolve_class_from_display_name(
-                participant,
-                participant_info.display_name.as_str(),
-            ) {
-                return resolution;
-            }
-
-            if let Some(resolution) = self.resolve_class_from_special_display_form(participant_info)
-            {
-                return resolution;
-            }
-        }
-
-        self.resolve_by_class_name(participant)
+        ParticipantResolution::Missing
     }
 
     fn resolve_class_from_participant(
@@ -340,103 +320,17 @@ impl<'a> ClassDesignSequenceValidator<'a> {
             .map(ParticipantResolution::Matched)
     }
 
-    fn resolve_class_from_display_name(
-        &self,
-        participant: &str,
-        display_name: &str,
-    ) -> Option<ParticipantResolution<'a>> {
-        if display_name == participant {
-            return None;
-        }
-
-        if let Some(entity) = self.resolve_by_class_id(display_name) {
-            return Some(ParticipantResolution::Matched(entity));
-        }
-
-        match self.resolve_by_class_name(display_name) {
-            ParticipantResolution::Missing => None,
-            matched_or_ambiguous => Some(matched_or_ambiguous),
-        }
-    }
-
-    fn resolve_class_from_special_display_form(
-        &self,
-        participant_info: &SequenceParticipantInfo,
-    ) -> Option<ParticipantResolution<'a>> {
-        let display_candidates = class_match_candidates_from_display(participant_info);
-
-        for id_candidate in display_candidates.id_candidates {
-            if let Some(entity) = self.resolve_by_class_id(&id_candidate) {
-                return Some(ParticipantResolution::Matched(entity));
-            }
-        }
-
-        for name_candidate in display_candidates.name_candidates {
-            match self.resolve_by_class_name(&name_candidate) {
-                ParticipantResolution::Missing => {}
-                matched_or_ambiguous => return Some(matched_or_ambiguous),
-            }
-        }
-
-        None
-    }
-
-    fn report_unsupported_participant_display_name(
-        &mut self,
-        participant: &str,
-        participant_info: &SequenceParticipantInfo,
-        source_file: &str,
-        source_line: u32,
-        display_issue: UnsupportedParticipantDisplayForm,
-    ) {
-        self.result.add_failure(
-            ErrorBuilder::new(ErrorCategory::Class)
-                .title(format!(
-                    "sequence participant \"{participant}\" uses an invalid kind of display name"
-                ))
-                .field("participant", format!("\"{participant}\""))
-                .field("display name", format!("\"{}\"", participant_info.display_name))
-                .field(
-                    "invalid form",
-                    display_issue.invalid_form(&participant_info.display_name),
-                )
-                .field("sequence source file", format!("\"{source_file}\""))
-                .field("sequence source line", source_line.to_string())
-                .fix(
-                    "use one supported form such as :Name, prefix:qualified::Type, or provide an unambiguous alias"
-                        .to_string(),
-                )
-                .build(),
-        );
-    }
-
     fn resolve_by_class_id(&self, reference: &str) -> Option<&'a class_diagram::SimpleEntity> {
         if let Some(entity) = self.design_classes.find_by_id(reference) {
             return Some(entity);
         }
 
         let normalized_reference = SequenceParticipantInfo::normalize_qualified_name(reference);
-        if normalized_reference == reference {
-            return None;
+        if normalized_reference != reference {
+            return self.design_classes.find_by_id(&normalized_reference);
         }
 
-        self.design_classes.find_by_id(&normalized_reference)
-    }
-
-    fn resolve_by_class_name(&self, class_name: &str) -> ParticipantResolution<'a> {
-        let short_name_matches: Vec<_> = self
-            .design_classes
-            .entities()
-            .filter(|entity| entity.name == class_name)
-            .collect();
-
-        match short_name_matches.as_slice() {
-            [] => ParticipantResolution::Missing,
-            [entity] => ParticipantResolution::Matched(entity),
-            entities => ParticipantResolution::Ambiguous(
-                entities.iter().map(|entity| entity.id.clone()).collect(),
-            ),
-        }
+        None
     }
 
     fn class_or_ancestors_define_method(
@@ -562,108 +456,98 @@ impl<'a> ClassDesignSequenceValidator<'a> {
 enum ParticipantResolution<'a> {
     Matched(&'a class_diagram::SimpleEntity),
     Missing,
-    Ambiguous(BTreeSet<String>),
-}
-
-#[derive(Default)]
-struct ClassMatchCandidates {
-    id_candidates: Vec<String>,
-    name_candidates: Vec<String>,
 }
 
-#[derive(Clone, Copy)]
-enum UnsupportedParticipantDisplayForm {
-    MultipleStandaloneColons,
-    EmptyColonSuffix,
-}
+fn display_sequence_participant_name(participant: &str) -> String {
+    let normalized_participant = SequenceParticipantInfo::normalize_qualified_name(participant);
 
-impl UnsupportedParticipantDisplayForm {
-    fn invalid_form(self, display_name: &str) -> String {
-        match self {
-            Self::MultipleStandaloneColons => format!(
-                "\"{}\" contains multiple standalone ':' separators",
-                display_name
-            ),
-            Self::EmptyColonSuffix => {
-                format!(
-                    "\"{}\" uses ':' without a non-empty right-hand side",
-                    display_name
-                )
-            }
-        }
+    if looks_like_qualified_class_id(&normalized_participant) {
+        display_reference_name(&normalized_participant).to_string()
+    } else {
+        participant.to_string()
     }
 }
 
-fn unsupported_participant_display_form(
-    participant_info: &SequenceParticipantInfo,
-) -> Option<UnsupportedParticipantDisplayForm> {
-    let primary_line = first_nonempty_display_line(&participant_info.display_name)?;
-    let separator_colons = separator_colon_positions(primary_line);
+fn display_sequence_participant_name_from_source(participant: &str, source_file: &str) -> String {
+    let normalized_participant = SequenceParticipantInfo::normalize_qualified_name(participant);
 
-    if separator_colons.len() > 1 {
-        return Some(UnsupportedParticipantDisplayForm::MultipleStandaloneColons);
+    if looks_like_qualified_class_id(&normalized_participant) {
+        display_name_from_source_path_in_context(
+            &normalized_participant,
+            source_file,
+            std::iter::empty(),
+        )
+    } else {
+        participant.to_string()
     }
-
-    if let Some(colon_index) = separator_colons.first() {
-        if primary_line[colon_index + 1..].trim().is_empty() {
-            return Some(UnsupportedParticipantDisplayForm::EmptyColonSuffix);
-        }
-    }
-
-    None
 }
 
-fn class_match_candidates_from_display(
-    participant_info: &SequenceParticipantInfo,
-) -> ClassMatchCandidates {
-    let Some(primary_line) = first_nonempty_display_line(&participant_info.display_name) else {
-        return ClassMatchCandidates::default();
-    };
+fn display_suggested_class_name(entity: &class_diagram::SimpleEntity) -> String {
+    let normalized_identifier = SequenceParticipantInfo::normalize_qualified_name(&entity.id);
+    let segments = normalized_identifier
+        .split('.')
+        .filter(|segment| !segment.is_empty())
+        .collect::<Vec<_>>();
 
-    let separator_colons = separator_colon_positions(primary_line);
-    if separator_colons.len() != 1 {
-        return ClassMatchCandidates::default();
+    match segments.as_slice() {
+        [] => String::new(),
+        [leaf] => (*leaf).to_string(),
+        [.., namespace, leaf] if should_display_namespace_segment(namespace) => {
+            format!("{namespace}.{leaf}")
+        }
+        [.., leaf] => (*leaf).to_string(),
     }
+}
 
-    let colon_index = separator_colons[0];
-    if colon_index == 0 {
-        let short_name = primary_line[1..].trim();
-        if short_name.is_empty() {
-            return ClassMatchCandidates::default();
-        }
+fn should_display_namespace_segment(segment: &str) -> bool {
+    segment
+        .chars()
+        .any(|character| character.is_ascii_uppercase())
+        || segment.chars().any(|character| character.is_ascii_digit())
+        || !segment.contains('_')
+}
 
-        return ClassMatchCandidates {
-            id_candidates: Vec::new(),
-            name_candidates: vec![short_name.to_string()],
-        };
-    }
+fn looks_like_qualified_class_id(reference: &str) -> bool {
+    let segments = reference
+        .trim()
+        .split(['.', ':'])
+        .filter(|segment| !segment.is_empty())
+        .collect::<Vec<_>>();
+
+    segments.len() > 1
+        && segments
+            .iter()
+            .all(|segment| is_identifier_segment(segment))
+}
 
-    let Some(type_text) = text_after_separator_colon(primary_line, colon_index) else {
-        return ClassMatchCandidates::default();
-    };
+fn looks_like_class_identifier(reference: &str) -> bool {
+    let segments = reference
+        .trim()
+        .split(['.', ':'])
+        .filter(|segment| !segment.is_empty())
+        .collect::<Vec<_>>();
+
+    !segments.is_empty()
+        && segments
+            .iter()
+            .all(|segment| is_identifier_segment(segment))
+}
 
-    class_match_candidates_from_type_text(type_text)
+fn is_identifier_segment(segment: &str) -> bool {
+    !segment.is_empty()
+        && segment
+            .chars()
+            .all(|character| character.is_ascii_alphanumeric() || character == '_')
 }
 
-fn participant_suggestion_queries(
-    participant: &str,
-    participant_info: &SequenceParticipantInfo,
-) -> Vec<String> {
+fn participant_suggestion_queries(participant: &str) -> Vec<String> {
     let mut queries = BTreeSet::new();
 
     insert_participant_suggestion_query(&mut queries, participant);
 
-    if participant_info.display_name != participant {
-        insert_participant_suggestion_query(&mut queries, &participant_info.display_name);
-    }
-
-    let display_candidates = class_match_candidates_from_display(participant_info);
-    for candidate in display_candidates
-        .id_candidates
-        .into_iter()
-        .chain(display_candidates.name_candidates)
-    {
-        insert_participant_suggestion_query(&mut queries, &candidate);
+    let display_participant = display_sequence_participant_name(participant);
+    if display_participant != participant {
+        insert_participant_suggestion_query(&mut queries, &display_participant);
     }
 
     queries.into_iter().collect()
@@ -682,95 +566,6 @@ fn insert_participant_suggestion_query(queries: &mut BTreeSet<String>, query: &s
     }
 }
 
-fn text_after_separator_colon(primary_line: &str, colon_index: usize) -> Option<&str> {
-    let type_text = primary_line[colon_index + 1..].trim();
-    (!type_text.is_empty()).then_some(type_text)
-}
-
-fn class_match_candidates_from_type_text(type_text: &str) -> ClassMatchCandidates {
-    let mut candidates = ClassMatchCandidates {
-        id_candidates: Vec::new(),
-        name_candidates: Vec::new(),
-    };
-
-    if type_text.contains("::") {
-        candidates.id_candidates.push(type_text.to_string());
-    }
-
-    candidates.name_candidates.push(type_text.to_string());
-
-    if let Some(short_name) = type_text.rsplit("::").next().map(str::trim) {
-        if !short_name.is_empty() && short_name != type_text {
-            candidates.name_candidates.push(short_name.to_string());
-        }
-    }
-
-    candidates
-}
-
-fn ignored_special_display_suffix(participant_info: &SequenceParticipantInfo) -> Option<String> {
-    let normalized_segments = normalized_display_segments(&participant_info.display_name);
-    let (primary_line, ignored_segments) = normalized_segments.split_first()?;
-    let separator_colons = separator_colon_positions(primary_line);
-
-    if separator_colons.len() != 1 || ignored_segments.is_empty() {
-        return None;
-    }
-
-    Some(ignored_segments.join(" | "))
-}
-
-fn first_nonempty_display_line(display_name: &str) -> Option<&str> {
-    normalized_display_segments(display_name).into_iter().next()
-}
-
-fn normalized_display_segments(display_name: &str) -> Vec<&str> {
-    let mut lines = Vec::new();
-
-    for physical_line in display_name.lines() {
-        for escaped_line in physical_line
-            .split("\\n")
-            .flat_map(|segment| segment.split("/n"))
-        {
-            let trimmed = escaped_line.trim();
-            if !trimmed.is_empty() {
-                lines.push(trimmed);
-            }
-        }
-    }
-
-    lines
-}
-
-fn separator_colon_positions(text: &str) -> Vec<usize> {
-    const COLON: u8 = b':';
-
-    let bytes = text.as_bytes();
-
-    bytes
-        .iter()
-        .enumerate()
-        .filter_map(|(index, byte)| {
-            if *byte != COLON {
-                return None;
-            }
-
-            let previous_is_colon = index > 0 && bytes[index - 1] == COLON;
-            let next_is_colon = index + 1 < bytes.len() && bytes[index + 1] == COLON;
-
-            (!previous_is_colon && !next_is_colon).then_some(index)
-        })
-        .collect()
-}
-
-fn format_name_set(names: &BTreeSet<String>) -> String {
-    names
-        .iter()
-        .map(|name| format!("\"{name}\""))
-        .collect::<Vec<_>>()
-        .join(", ")
-}
-
 fn append_debug_log(
     diagnostics: &mut Diagnostics,
     design_classes: &ClassEntityIndex,
diff --git a/validation/core/src/validators/component_internal_api_validator.rs b/validation/core/src/validators/component_internal_api_validator.rs
index ddcdf0fe..9a638615 100644
--- a/validation/core/src/validators/component_internal_api_validator.rs
+++ b/validation/core/src/validators/component_internal_api_validator.rs
@@ -16,7 +16,10 @@
 
 use std::collections::{BTreeMap, BTreeSet};
 
-use super::shared::{best_string_suggestion, earliest_source_by_id, format_name_list};
+use super::shared::{
+    best_string_suggestion, display_name_from_source_path_in_context, display_name_from_sources,
+    display_names_from_sources, earliest_source_by_id, format_name_list,
+};
 use crate::models::{ComponentDiagramArchitecture, InternalApiIndex, LogicComponentExt};
 use crate::results::{ErrorBuilder, ErrorCategory};
 use crate::{Diagnostics, ValidationResult};
@@ -123,7 +126,9 @@ fn format_missing_internal_api_interface_error(
     component_interface_sources: &BTreeMap<String, SourceLocation>,
     internal_api_interface_ids: &BTreeSet<String>,
 ) -> String {
-    let missing_interfaces = format_name_list(missing_internal_api_interfaces);
+    let missing_interface_display_names =
+        display_names_from_sources(missing_internal_api_interfaces, component_interface_sources);
+    let missing_interfaces = format_name_list(&missing_interface_display_names);
 
     let mut error = ErrorBuilder::new(ErrorCategory::Interface)
         .title(format!(
@@ -132,24 +137,37 @@ fn format_missing_internal_api_interface_error(
         .field("missing interfaces", missing_interfaces.clone());
 
     for interface_id in missing_internal_api_interfaces {
+        let display_interface_id =
+            display_name_from_sources(interface_id, component_interface_sources);
+
         if let Some(source_location) = component_interface_sources.get(interface_id) {
             let (source_file, source_line) = source_location.display();
             error = error
                 .field(
-                    format!("component source file for \"{interface_id}\""),
+                    format!("component source file for \"{display_interface_id}\""),
                     format!("\"{source_file}\""),
                 )
                 .field(
-                    format!("component source line for \"{interface_id}\""),
+                    format!("component source line for \"{display_interface_id}\""),
                     source_line.to_string(),
                 );
         }
 
+        let internal_candidates: BTreeSet<String> = internal_api_interface_ids
+            .iter()
+            .map(|interface_id| {
+                display_name_from_source_path_in_context(interface_id, "", std::iter::empty())
+            })
+            .collect();
         if let Some(suggested_interface) = best_string_suggestion(
-            interface_id,
-            internal_api_interface_ids.iter().map(String::as_str),
+            &display_interface_id,
+            internal_candidates.iter().map(String::as_str),
         ) {
-            error = error.suggest(interface_id, Some("interface"), &suggested_interface);
+            error = error.suggest(
+                &display_interface_id,
+                Some("interface"),
+                &suggested_interface,
+            );
         }
     }
 
diff --git a/validation/core/src/validators/component_public_api_validator.rs b/validation/core/src/validators/component_public_api_validator.rs
index 087ef049..c5bca916 100644
--- a/validation/core/src/validators/component_public_api_validator.rs
+++ b/validation/core/src/validators/component_public_api_validator.rs
@@ -16,7 +16,10 @@
 
 use std::collections::{BTreeMap, BTreeSet};
 
-use super::shared::{best_string_suggestion, earliest_source_by_id, format_name_list};
+use super::shared::{
+    best_string_suggestion, display_name_from_sources, display_names_from_sources,
+    display_reference_name_set, earliest_source_by_id, format_name_list, normalize,
+};
 use crate::models::{ComponentDiagramArchitecture, LogicComponentExt, PublicApiIndex};
 use crate::results::{ErrorBuilder, ErrorCategory};
 use crate::{Diagnostics, ValidationResult};
@@ -35,7 +38,7 @@ struct ComponentPublicApiValidator {
     component_public_api_sources: BTreeMap<String, SourceLocation>,
     /// Public API interfaces referenced by relationships from SEooC entities.
     seooc_related_public_api_ids: BTreeSet<String>,
-    /// Public API interfaces declared in the public API class diagram.
+    /// Public API interface ids declared in the public API class diagram.
     design_public_api_ids: BTreeSet<String>,
     result: ValidationResult,
 }
@@ -48,7 +51,7 @@ impl ComponentPublicApiValidator {
         Self {
             seooc_related_public_api_ids: collect_seooc_related_public_api_ids(component_diagram),
             component_public_api_sources: collect_component_public_api_sources(component_diagram),
-            design_public_api_ids: public_api_index.api_names().cloned().collect(),
+            design_public_api_ids: public_api_index.api_ids().cloned().collect(),
             result: ValidationResult::default(),
         }
     }
@@ -72,7 +75,10 @@ impl ComponentPublicApiValidator {
         let component_public_api_ids: BTreeSet<String> =
             self.component_public_api_sources.keys().cloned().collect();
         let missing_public_apis: BTreeSet<String> = component_public_api_ids
-            .difference(&self.design_public_api_ids)
+            .iter()
+            .filter(|component_id| {
+                !has_matching_public_api_id(component_id, &self.design_public_api_ids)
+            })
             .cloned()
             .collect();
 
@@ -102,6 +108,15 @@ impl ComponentPublicApiValidator {
     }
 }
 
+fn has_matching_public_api_id(
+    component_id: &str,
+    design_public_api_ids: &BTreeSet<String>,
+) -> bool {
+    design_public_api_ids
+        .iter()
+        .any(|design_id| normalize(component_id) == normalize(design_id))
+}
+
 fn append_debug_log(
     diagnostics: &mut Diagnostics,
     component_public_api_ids: &BTreeSet<String>,
@@ -118,7 +133,7 @@ fn append_debug_log(
         diagnostics.debug(|| format!("  {api_id}"));
     }
 
-    diagnostics.debug(|| "Public API entries available for component public APIs:".to_string());
+    diagnostics.debug(|| "Public API ids available for component public APIs:".to_string());
     for api_id in design_public_api_ids {
         diagnostics.debug(|| format!("  {api_id}"));
     }
@@ -160,9 +175,14 @@ fn format_missing_public_api_error(
     component_public_api_sources: &BTreeMap<String, SourceLocation>,
     design_public_api_ids: &BTreeSet<String>,
 ) -> String {
-    let missing_public_api_names = format_name_list(missing_public_apis);
-    let case_mismatch_public_apis =
-        collect_case_mismatch_public_apis(missing_public_apis, design_public_api_ids);
+    let display_missing_public_apis =
+        display_names_from_sources(missing_public_apis, component_public_api_sources);
+    let missing_public_api_names = format_name_list(&display_missing_public_apis);
+    let display_design_public_api_ids = display_reference_name_set(design_public_api_ids);
+    let case_mismatch_public_apis = collect_case_mismatch_public_apis(
+        &display_missing_public_apis,
+        &display_design_public_api_ids,
+    );
     let has_case_mismatch = !case_mismatch_public_apis.is_empty();
     let case_mismatch_names = format_name_list(&case_mismatch_public_apis);
     let case_mismatch_title_suffix = if has_case_mismatch {
@@ -183,28 +203,38 @@ fn format_missing_public_api_error(
         .field("missing public APIs", missing_public_api_names.clone());
 
     for interface_id in missing_public_apis {
+        let display_interface_id =
+            display_name_from_sources(interface_id, component_public_api_sources);
+
         if let Some(source_location) = component_public_api_sources.get(interface_id) {
             let (source_file, source_line) = source_location.display();
             error = error
                 .field(
-                    format!("static source file for \"{interface_id}\""),
+                    format!("static source file for \"{display_interface_id}\""),
                     format!("\"{source_file}\""),
                 )
                 .field(
-                    format!("static source line for \"{interface_id}\""),
+                    format!("static source line for \"{display_interface_id}\""),
                     source_line.to_string(),
                 );
         }
 
-        if case_mismatch_public_apis.contains(interface_id) {
+        if case_mismatch_public_apis
+            .iter()
+            .any(|name| name.eq_ignore_ascii_case(&display_interface_id))
+        {
             continue;
         }
 
         if let Some(suggested_interface) = best_string_suggestion(
-            interface_id,
-            design_public_api_ids.iter().map(String::as_str),
+            &display_interface_id,
+            display_design_public_api_ids.iter().map(String::as_str),
         ) {
-            error = error.suggest(interface_id, Some("interface"), &suggested_interface);
+            error = error.suggest(
+                &display_interface_id,
+                Some("interface"),
+                &suggested_interface,
+            );
         }
     }
 
@@ -234,7 +264,9 @@ fn format_unrelated_public_api_error(
     unrelated_public_apis: &BTreeSet<String>,
     component_public_api_sources: &BTreeMap<String, SourceLocation>,
 ) -> String {
-    let public_api_names = format_name_list(unrelated_public_apis);
+    let display_unrelated_public_apis =
+        display_names_from_sources(unrelated_public_apis, component_public_api_sources);
+    let public_api_names = format_name_list(&display_unrelated_public_apis);
 
     let mut error = ErrorBuilder::new(ErrorCategory::Interface)
         .title(format!(
@@ -243,15 +275,18 @@ fn format_unrelated_public_api_error(
         .field("public APIs", public_api_names.clone());
 
     for interface_id in unrelated_public_apis {
+        let display_interface_id =
+            display_name_from_sources(interface_id, component_public_api_sources);
+
         if let Some(source_location) = component_public_api_sources.get(interface_id) {
             let (source_file, source_line) = source_location.display();
             error = error
                 .field(
-                    format!("static source file for \"{interface_id}\""),
+                    format!("static source file for \"{display_interface_id}\""),
                     format!("\"{source_file}\""),
                 )
                 .field(
-                    format!("static source line for \"{interface_id}\""),
+                    format!("static source line for \"{display_interface_id}\""),
                     source_line.to_string(),
                 );
         }
diff --git a/validation/core/src/validators/component_sequence_validator.rs b/validation/core/src/validators/component_sequence_validator.rs
index 1c2c66af..167f43ea 100644
--- a/validation/core/src/validators/component_sequence_validator.rs
+++ b/validation/core/src/validators/component_sequence_validator.rs
@@ -17,7 +17,9 @@
 use std::collections::{BTreeMap, BTreeSet};
 
 use super::shared::{
-    best_string_suggestion, build_observed_call_contexts, build_unit_bindings, format_name_list,
+    best_string_suggestion, build_observed_call_contexts, build_unit_bindings,
+    display_name_from_source_path_in_context, display_names_without_common_prefix,
+    display_unit_pair_from_optional_source_paths, format_display_names, format_name_list,
     intersect_interfaces, SequenceCallContext, UnitBindings,
 };
 use crate::models::{
@@ -48,17 +50,17 @@ struct ComponentSequenceValidator<'a> {
 impl SequenceCallContext<'_> {
     fn normalized_left_unit(&self) -> &str {
         if self.caller_unit <= self.callee_unit {
-            self.caller_unit
+            &self.caller_unit
         } else {
-            self.callee_unit
+            &self.callee_unit
         }
     }
 
     fn normalized_right_unit(&self) -> &str {
         if self.caller_unit <= self.callee_unit {
-            self.callee_unit
+            &self.callee_unit
         } else {
-            self.caller_unit
+            &self.caller_unit
         }
     }
 
@@ -85,8 +87,11 @@ impl<'a> ComponentSequenceValidator<'a> {
         sequence_diagram: &'a SequenceDiagramIndex,
     ) -> Self {
         let unit_bindings = build_unit_bindings(component_diagram);
-        let observed_call_contexts =
-            build_observed_call_contexts(sequence_diagram.observed_calls(), &unit_bindings);
+        let observed_call_contexts = build_observed_call_contexts(
+            sequence_diagram.observed_calls(),
+            sequence_diagram.participants(),
+            &unit_bindings,
+        );
 
         Self {
             participants: sequence_diagram.participants(),
@@ -110,37 +115,52 @@ impl<'a> ComponentSequenceValidator<'a> {
     }
 
     fn check_consistency(&mut self) {
-        self.check_participant_aliases();
+        self.check_participant_uids();
         self.check_interface_connected_units_have_sequence_calls();
         self.check_sequence_calls_have_interface_connections();
     }
 
-    fn check_participant_aliases(&mut self) {
-        for alias in self
+    fn check_participant_uids(&mut self) {
+        let declared_unit_ids: BTreeSet<String> = self
+            .participants
+            .iter()
+            .filter(|(participant, _)| !is_external_endpoint(participant))
+            .map(|(participant, _)| (*participant).clone())
+            .filter(|unit_id| self.unit_bindings.contains_key(unit_id))
+            .collect();
+
+        for unit_id in self
             .unit_bindings
             .keys()
-            .filter(|alias| !self.participants.contains_key(*alias))
+            .filter(|unit_id| !declared_unit_ids.contains(*unit_id))
         {
             let (source_file, source_line) = self
                 .unit_bindings
-                .get(alias)
+                .get(unit_id)
                 .and_then(|bindings| bindings.source_location.as_ref())
                 .map(|source_location| source_location.display())
                 .unwrap_or_default();
+            let display_name = display_missing_unit_name(
+                unit_id,
+                &source_file,
+                self.participants.keys().map(String::as_str),
+            );
 
             let error = ErrorBuilder::new(ErrorCategory::Naming)
                 .title(format!(
-                    "alias \"{alias}\" from the component diagram not found in the sequence diagram"
+                    "unit id \"{}\" from the component diagram not found as a participant uid in the sequence diagram",
+                    display_name
                 ))
-                .field("alias", format!("\"{alias}\""))
+                .field("unit id", format!("\"{display_name}\""))
                 .field("component source file", format!("\"{source_file}\""))
                 .field("component source line", source_line.to_string())
                 .fix(format!(
-                    "add sequence participant \"{alias}\" in the sequence diagram, or remove it from the component diagram"
+                    "add sequence participant uid \"{}\" in the sequence diagram, or remove it from the component diagram",
+                    display_name
                 ));
 
             let error = if let Some(suggested_name) = best_string_suggestion(
-                alias,
+                unit_id,
                 self.participants
                     .keys()
                     .filter(|participant| !is_external_endpoint(participant))
@@ -148,7 +168,11 @@ impl<'a> ComponentSequenceValidator<'a> {
             )
             .as_deref()
             {
-                error.suggest(alias, None, suggested_name)
+                error.suggest(
+                    &display_name,
+                    None,
+                    &display_missing_unit_suggestion(suggested_name),
+                )
             } else {
                 error
             };
@@ -156,28 +180,42 @@ impl<'a> ComponentSequenceValidator<'a> {
             self.result.add_failure(error.build());
         }
 
-        for participant in self.participants.keys().filter(|participant| {
-            !is_external_endpoint(participant) && !self.unit_bindings.contains_key(*participant)
+        for participant_uid in self.participants.keys().filter(|participant_uid| {
+            !is_external_endpoint(participant_uid)
+                && !self.unit_bindings.contains_key(*participant_uid)
         }) {
             let (source_file, source_line) =
-                self.participants[participant].source_location.display();
+                self.participants[participant_uid].source_location.display();
+            let display_name = display_missing_unit_name(
+                participant_uid,
+                &source_file,
+                self.unit_bindings.keys().map(String::as_str),
+            );
 
             let error = ErrorBuilder::new(ErrorCategory::Naming)
                 .title(format!(
-                    "participant \"{participant}\" from the sequence diagram not found in the component diagram"
+                    "participant uid \"{}\" from the sequence diagram not found in the component diagram",
+                    display_name
                 ))
-                .field("participant", format!("\"{participant}\""))
+                .field("participant uid", format!("\"{display_name}\""))
                 .field("sequence source file", format!("\"{source_file}\""))
                 .field("sequence source line", source_line.to_string())
                 .fix(format!(
-                    "add component unit alias \"{participant}\" in the component diagram, or remove it from the sequence diagram"
+                    "add component unit id \"{}\" in the component diagram, or remove it from the sequence diagram",
+                    display_name
                 ));
 
-            let error = if let Some(suggested_name) =
-                best_string_suggestion(participant, self.unit_bindings.keys().map(String::as_str))
-                    .as_deref()
+            let error = if let Some(suggested_name) = best_string_suggestion(
+                participant_uid,
+                self.unit_bindings.keys().map(String::as_str),
+            )
+            .as_deref()
             {
-                error.suggest(participant, None, suggested_name)
+                error.suggest(
+                    &display_name,
+                    None,
+                    &display_missing_unit_suggestion(suggested_name),
+                )
             } else {
                 error
             };
@@ -192,13 +230,16 @@ impl<'a> ComponentSequenceValidator<'a> {
                 continue;
             }
 
-            let unit_pair = format_unit_pair(left_unit, right_unit);
-            let shared_interfaces = format_name_list(interfaces);
+            let unit_pair =
+                format_component_connected_unit_pair(&self.unit_bindings, left_unit, right_unit);
+            let shared_interfaces = format_trimmed_interface_list(interfaces);
             let remove_connection_fix = if interfaces.len() == 1 {
                 "remove that shared interface connection from the component diagram"
             } else {
                 "remove those shared interface connections from the component diagram"
             };
+            let [left_display, right_display] =
+                displayed_component_connected_unit_pair(&self.unit_bindings, left_unit, right_unit);
             let (left_source_file, left_source_line) = unit_source(&self.unit_bindings, left_unit);
             let (right_source_file, right_source_line) =
                 unit_source(&self.unit_bindings, right_unit);
@@ -206,28 +247,28 @@ impl<'a> ComponentSequenceValidator<'a> {
             self.result.add_failure(
                 ErrorBuilder::new(ErrorCategory::Interface)
                     .title(format!(
-                        "component-connected units \"{left_unit}\" and \"{right_unit}\" have no corresponding function-call in the sequence diagram"
+                        "component-connected units \"{left_display}\" and \"{right_display}\" have no corresponding function-call in the sequence diagram"
                     ))
                     .field("unit pair", unit_pair)
                     .field(
-                        format!("component source file for \"{left_unit}\""),
+                        format!("component source file for \"{left_display}\""),
                         format!("\"{left_source_file}\""),
                     )
                     .field(
-                        format!("component source line for \"{left_unit}\""),
+                        format!("component source line for \"{left_display}\""),
                         left_source_line.to_string(),
                     )
                     .field(
-                        format!("component source file for \"{right_unit}\""),
+                        format!("component source file for \"{right_display}\""),
                         format!("\"{right_source_file}\""),
                     )
                     .field(
-                        format!("component source line for \"{right_unit}\""),
+                        format!("component source line for \"{right_display}\""),
                         right_source_line.to_string(),
                     )
                     .field("shared interfaces", shared_interfaces.clone())
                     .fix(format!(
-                        "add a function-call between \"{left_unit}\" and \"{right_unit}\" in the sequence diagram, or {remove_connection_fix}"
+                        "add a function-call between \"{left_display}\" and \"{right_display}\" in the sequence diagram, or {remove_connection_fix}"
                     ))
                     .build(),
             );
@@ -269,23 +310,32 @@ impl<'a> ComponentSequenceValidator<'a> {
 
             let left_unit = call_context.normalized_left_unit();
             let right_unit = call_context.normalized_right_unit();
-            let unit_pair = format_unit_pair(left_unit, right_unit);
-            let left_interface_label = format!("interfaces for \"{left_unit}\"");
-            let right_interface_label = format!("interfaces for \"{right_unit}\"");
+            let unit_pair =
+                format_component_connected_unit_pair(&self.unit_bindings, left_unit, right_unit);
+            let [left_display, right_display] =
+                displayed_component_connected_unit_pair(&self.unit_bindings, left_unit, right_unit);
+            let left_interface_label = format!("interfaces for \"{left_display}\"");
+            let right_interface_label = format!("interfaces for \"{right_display}\"");
             let (source_file, source_line) = sequence_call_source(call_context);
 
             self.result.add_failure(
                 ErrorBuilder::new(ErrorCategory::Interface)
                     .title(format!(
-                        "sequence-connected units \"{left_unit}\" and \"{right_unit}\" have no corresponding shared interface connection in the component diagram."
+                        "sequence-connected units \"{left_display}\" and \"{right_display}\" have no corresponding shared interface connection in the component diagram."
                     ))
                     .field("unit pair", unit_pair)
                     .field("sequence source file", format!("\"{source_file}\""))
                     .field("sequence source line", source_line.to_string())
-                    .field(&left_interface_label, format_name_list(left_interfaces))
-                    .field(&right_interface_label, format_name_list(right_interfaces))
+                    .field(
+                        &left_interface_label,
+                        format_trimmed_interface_list(left_interfaces),
+                    )
+                    .field(
+                        &right_interface_label,
+                        format_trimmed_interface_list(right_interfaces),
+                    )
                     .fix(format!(
-                        "add a shared interface connection between \"{left_unit}\" and \"{right_unit}\" in the component diagram, or remove that function-call from the sequence diagram"
+                        "add a shared interface connection between \"{left_display}\" and \"{right_display}\" in the component diagram, or remove that function-call from the sequence diagram."
                     ))
                     .build(),
             );
@@ -294,7 +344,8 @@ impl<'a> ComponentSequenceValidator<'a> {
 }
 
 fn call_involves_external_endpoint(call_context: &SequenceCallContext<'_>) -> bool {
-    is_external_endpoint(call_context.caller_unit) || is_external_endpoint(call_context.callee_unit)
+    is_external_endpoint(&call_context.caller_unit)
+        || is_external_endpoint(&call_context.callee_unit)
 }
 
 fn append_debug_log<'a>(
@@ -304,14 +355,14 @@ fn append_debug_log<'a>(
     unit_bindings: &UnitBindings,
     connected_unit_pairs: &BTreeMap<(String, String), BTreeSet<String>>,
 ) {
-    diagnostics.debug(|| "Expected unit aliases from component diagrams:".to_string());
-    for alias in unit_bindings.keys() {
-        diagnostics.debug(|| format!("  {alias}"));
+    diagnostics.debug(|| "Expected unit ids from component diagrams:".to_string());
+    for unit_id in unit_bindings.keys() {
+        diagnostics.debug(|| format!("  {unit_id}"));
     }
 
-    diagnostics.debug(|| "Observed participants from sequence diagrams:".to_string());
-    for participant in observed_participants {
-        diagnostics.debug(|| format!("  {participant}"));
+    diagnostics.debug(|| "Observed participant uids from sequence diagrams:".to_string());
+    for participant_uid in observed_participants {
+        diagnostics.debug(|| format!("  {participant_uid}"));
     }
 
     diagnostics.debug(|| "Observed sequence calls from sequence diagrams:".to_string());
@@ -325,10 +376,10 @@ fn append_debug_log<'a>(
     }
 
     diagnostics.debug(|| "Unit interface targets from component diagrams:".to_string());
-    for (unit_alias, bindings) in unit_bindings {
+    for (unit_id, bindings) in unit_bindings {
         diagnostics.debug(|| {
             format!(
-                "  {unit_alias} -> {}",
+                "  {unit_id} -> {}",
                 format_name_list(&bindings.all_interfaces)
             )
         });
@@ -344,14 +395,14 @@ fn build_connected_unit_pairs(
     unit_bindings: &UnitBindings,
 ) -> BTreeMap<(String, String), BTreeSet<String>> {
     let mut connected_unit_pairs = BTreeMap::new();
-    let aliases: Vec<&String> = unit_bindings.keys().collect();
-
-    for index in 0..aliases.len() {
-        for other_index in (index + 1)..aliases.len() {
-            let left_alias = aliases[index];
-            let right_alias = aliases[other_index];
-            let left_bindings = &unit_bindings[left_alias];
-            let right_bindings = &unit_bindings[right_alias];
+    let unit_ids: Vec<&String> = unit_bindings.keys().collect();
+
+    for index in 0..unit_ids.len() {
+        for other_index in (index + 1)..unit_ids.len() {
+            let left_unit_id = unit_ids[index];
+            let right_unit_id = unit_ids[other_index];
+            let left_bindings = &unit_bindings[left_unit_id];
+            let right_bindings = &unit_bindings[right_unit_id];
             let mut shared_interfaces = intersect_interfaces(
                 &left_bindings.required_interfaces,
                 &right_bindings.provided_interfaces,
@@ -365,17 +416,19 @@ fn build_connected_unit_pairs(
                 continue;
             }
 
-            connected_unit_pairs
-                .insert((left_alias.clone(), right_alias.clone()), shared_interfaces);
+            connected_unit_pairs.insert(
+                (left_unit_id.clone(), right_unit_id.clone()),
+                shared_interfaces,
+            );
         }
     }
 
     connected_unit_pairs
 }
 
-fn unit_source(unit_bindings: &UnitBindings, unit_alias: &str) -> (String, u32) {
+fn unit_source(unit_bindings: &UnitBindings, unit_id: &str) -> (String, u32) {
     unit_bindings
-        .get(unit_alias)
+        .get(unit_id)
         .and_then(|bindings| bindings.source_location.as_ref())
         .map(|source_location| source_location.display())
         .unwrap_or_default()
@@ -385,8 +438,50 @@ fn sequence_call_source(call_context: &SequenceCallContext<'_>) -> (String, u32)
     call_context.source_location.display()
 }
 
-fn format_unit_pair(left_unit: &str, right_unit: &str) -> String {
-    format!("\"{left_unit}\" <-> \"{right_unit}\"")
+fn format_component_connected_unit_pair(
+    unit_bindings: &UnitBindings,
+    left_unit: &str,
+    right_unit: &str,
+) -> String {
+    let [left_display, right_display] =
+        displayed_component_connected_unit_pair(unit_bindings, left_unit, right_unit);
+
+    format!("\"{left_display}\" <-> \"{right_display}\"")
+}
+
+fn displayed_component_connected_unit_pair(
+    unit_bindings: &UnitBindings,
+    left: &str,
+    right: &str,
+) -> [String; 2] {
+    let (left_source_file, _) = unit_source(unit_bindings, left);
+    let (right_source_file, _) = unit_source(unit_bindings, right);
+
+    display_unit_pair_from_optional_source_paths(
+        left,
+        (!left_source_file.is_empty()).then_some(left_source_file.as_str()),
+        right,
+        (!right_source_file.is_empty()).then_some(right_source_file.as_str()),
+    )
+}
+
+fn format_trimmed_interface_list(names: &BTreeSet<String>) -> String {
+    format_display_names(names.iter().map(String::as_str), 2)
+}
+
+fn display_missing_unit_name<'a>(
+    target: &'a str,
+    source_file: &str,
+    other_names: impl Iterator<Item = &'a str>,
+) -> String {
+    display_name_from_source_path_in_context(target, source_file, other_names)
+}
+
+fn display_missing_unit_suggestion(name: &str) -> String {
+    display_names_without_common_prefix([name], 3)
+        .into_iter()
+        .next()
+        .unwrap_or_else(|| name.to_string())
 }
 
 #[cfg(test)]
diff --git a/validation/core/src/validators/mod.rs b/validation/core/src/validators/mod.rs
index ba23d7ad..a14ee7fd 100644
--- a/validation/core/src/validators/mod.rs
+++ b/validation/core/src/validators/mod.rs
@@ -20,7 +20,7 @@ mod component_internal_api_validator;
 mod component_public_api_validator;
 mod component_sequence_validator;
 mod sequence_internal_api_validator;
-mod shared;
+pub(crate) mod shared;
 
 #[cfg(test)]
 #[path = "test/fixtures.rs"]
diff --git a/validation/core/src/validators/sequence_internal_api_validator.rs b/validation/core/src/validators/sequence_internal_api_validator.rs
index 1d42f4be..34c15a61 100644
--- a/validation/core/src/validators/sequence_internal_api_validator.rs
+++ b/validation/core/src/validators/sequence_internal_api_validator.rs
@@ -18,9 +18,10 @@
 use std::collections::{BTreeMap, BTreeSet};
 
 use super::shared::{
-    best_string_suggestion, build_observed_call_contexts, build_unit_bindings, extract_method_name,
-    format_name_list, format_sequence_call, intersect_interfaces, SequenceCallContext,
-    UnitBindings, UnitInterfaces,
+    best_string_suggestion, build_observed_call_contexts, build_unit_bindings,
+    display_name_from_source_path_in_context, display_names,
+    display_unit_pair_from_optional_source_paths, extract_method_name, format_name_list,
+    format_sequence_call, intersect_interfaces, SequenceCallContext, UnitBindings, UnitInterfaces,
 };
 use crate::models::{
     ComponentDiagramArchitecture, InternalApiIndex, InternalApiInterface, LogicComponentExt,
@@ -166,6 +167,7 @@ impl<'a> SequenceInternalApiValidator<'a> {
                 candidate_method_names.iter().map(String::as_str),
             );
             return Some(format_sequence_method_consistency_error(
+                &component_context.unit_bindings,
                 call_context,
                 method_name,
                 "sequence function name was not found in available interface methods",
@@ -188,8 +190,8 @@ impl<'a> SequenceInternalApiValidator<'a> {
             return None;
         }
 
-        if units_with_missing_internal_api_interfaces.contains(call_context.caller_unit)
-            || units_with_missing_internal_api_interfaces.contains(call_context.callee_unit)
+        if units_with_missing_internal_api_interfaces.contains(&call_context.caller_unit)
+            || units_with_missing_internal_api_interfaces.contains(&call_context.callee_unit)
         {
             // The component-internal-api validator reports missing interface declarations first.
             return None;
@@ -223,6 +225,7 @@ impl<'a> SequenceInternalApiValidator<'a> {
                 candidate_method_names.iter().map(String::as_str),
             );
             return Some(format_sequence_method_consistency_error(
+                &component_context.unit_bindings,
                 call_context,
                 method_name,
                 "sequence function name was not found in the related interface methods",
@@ -247,10 +250,10 @@ impl<'a> SequenceInternalApiValidator<'a> {
     ) -> Option<String> {
         let caller_bindings = component_context
             .unit_bindings
-            .get(call_context.caller_unit)?;
+            .get(&call_context.caller_unit)?;
         let callee_bindings = component_context
             .unit_bindings
-            .get(call_context.callee_unit)?;
+            .get(&call_context.callee_unit)?;
 
         let caller_method_role_interfaces =
             intersect_interfaces(shared_method_interfaces, &role_interfaces(caller_bindings));
@@ -288,6 +291,7 @@ impl<'a> SequenceInternalApiValidator<'a> {
 
         if directional_method_interfaces.is_empty() {
             return Some(format_sequence_role_consistency_error(
+                &component_context.unit_bindings,
                 call_context,
                 method_name,
                 shared_method_interfaces,
@@ -339,11 +343,12 @@ fn append_debug_log(
             });
         }
 
-        diagnostics.debug(|| "Unit interface targets from component diagrams:".to_string());
-        for (unit_alias, bindings) in &component_context.unit_bindings {
+        diagnostics
+            .debug(|| "Unit interface targets from component diagrams (by unit id):".to_string());
+        for (unit_id, bindings) in &component_context.unit_bindings {
             diagnostics.debug(|| {
                 format!(
-                    "  {unit_alias} -> {}",
+                    "  {unit_id} -> {}",
                     format_name_list(&bindings.all_interfaces)
                 )
             });
@@ -378,8 +383,11 @@ fn build_component_context<'a>(
 ) -> ComponentContext<'a> {
     let unit_bindings = build_unit_bindings(component_diagram);
     let all_interfaces = build_all_interfaces(component_diagram, internal_api_diagram);
-    let observed_call_contexts =
-        build_observed_call_contexts(sequence_diagram.observed_calls(), &unit_bindings);
+    let observed_call_contexts = build_observed_call_contexts(
+        sequence_diagram.observed_calls(),
+        sequence_diagram.participants(),
+        &unit_bindings,
+    );
 
     ComponentContext {
         observed_call_contexts,
@@ -479,7 +487,7 @@ fn collect_units_with_missing_internal_api_interfaces(
                 !internal_api_interfaces_by_id.contains_key(interface_id.as_str())
             })
         })
-        .map(|(unit_alias, _)| unit_alias.clone())
+        .map(|(unit_id, _)| unit_id.clone())
         .collect()
 }
 
@@ -504,32 +512,36 @@ fn format_interface_method_coverage_error(
 ) -> String {
     let missing_functions = format_name_list(missing_methods);
     let (source_file, source_line) = interface.source_location.display();
+    let display_interface_id =
+        display_internal_api_interface_name(interface.id.as_str(), &source_file);
 
     ErrorBuilder::new(ErrorCategory::Coverage)
         .title(format!(
             "methods {missing_functions} declared on internal API interface \"{}\" in the internal API diagram are not exercised in the sequence diagram",
-            interface.id
+            display_interface_id
         ))
-        .field("interface id", format!("\"{}\"", interface.id))
+        .field("interface id", format!("\"{}\"", display_interface_id))
         .field("internal API source file", format!("\"{source_file}\""))
         .field("internal API source line", source_line.to_string())
         .field("missing functions", missing_functions.clone())
         .fix(format!(
             "add sequence interactions for functions {missing_functions} in the sequence diagram, or remove function declarations {missing_functions} in internal API interface \"{}\"",
-            interface.id
+            display_interface_id
         ))
         .build()
 }
 
 fn format_sequence_method_consistency_error(
+    unit_bindings: &UnitBindings,
     call_context: &SequenceCallContext<'_>,
     method_name: &str,
     description: &str,
     suggested_method: Option<&str>,
 ) -> String {
-    let sequence_call = format_sequence_call(
-        call_context.caller_unit,
-        call_context.callee_unit,
+    let sequence_call = format_displayed_sequence_call(
+        unit_bindings,
+        &call_context.caller_unit,
+        &call_context.callee_unit,
         method_name,
     );
     let (source_file, source_line) = call_context.source_location.display();
@@ -555,17 +567,23 @@ fn format_sequence_method_consistency_error(
 }
 
 fn format_sequence_role_consistency_error(
+    unit_bindings: &UnitBindings,
     call_context: &SequenceCallContext<'_>,
     method_name: &str,
     expected_interfaces: &BTreeSet<String>,
 ) -> String {
-    let sequence_call = format_sequence_call(
-        call_context.caller_unit,
-        call_context.callee_unit,
+    let sequence_call = format_displayed_sequence_call(
+        unit_bindings,
+        &call_context.caller_unit,
+        &call_context.callee_unit,
         method_name,
     );
-
-    let expected_interfaces = format_name_list(expected_interfaces);
+    let [displayed_caller_unit, displayed_callee_unit] = display_trimmed_unit_pair(
+        unit_bindings,
+        &call_context.caller_unit,
+        &call_context.callee_unit,
+    );
+    let expected_interfaces = format_trimmed_interface_list(expected_interfaces);
     let (source_file, source_line) = call_context.source_location.display();
 
     ErrorBuilder::new(ErrorCategory::Interface)
@@ -579,14 +597,14 @@ fn format_sequence_role_consistency_error(
             "expected caller role",
             format!(
                 "\"{}\" should require shared interface(s) {}",
-                call_context.caller_unit, expected_interfaces
+                displayed_caller_unit, expected_interfaces
             ),
         )
         .field(
             "expected callee role",
             format!(
                 "\"{}\" should provide shared interface(s) {}",
-                call_context.callee_unit, expected_interfaces
+                displayed_callee_unit, expected_interfaces
             ),
         )
         .fix(format!(
@@ -595,6 +613,50 @@ fn format_sequence_role_consistency_error(
         .build()
 }
 
+fn format_displayed_sequence_call(
+    unit_bindings: &UnitBindings,
+    caller_unit: &str,
+    callee_unit: &str,
+    method_name: &str,
+) -> String {
+    let [displayed_caller_unit, displayed_callee_unit] =
+        display_trimmed_unit_pair(unit_bindings, caller_unit, callee_unit);
+
+    format_sequence_call(&displayed_caller_unit, &displayed_callee_unit, method_name)
+}
+
+fn display_trimmed_unit_pair(unit_bindings: &UnitBindings, left: &str, right: &str) -> [String; 2] {
+    let left_source_file = unit_source_file(unit_bindings, left);
+    let right_source_file = unit_source_file(unit_bindings, right);
+
+    display_unit_pair_from_optional_source_paths(
+        left,
+        (!left_source_file.is_empty()).then_some(left_source_file.as_str()),
+        right,
+        (!right_source_file.is_empty()).then_some(right_source_file.as_str()),
+    )
+}
+
+fn unit_source_file(unit_bindings: &UnitBindings, unit_id: &str) -> String {
+    unit_bindings
+        .get(unit_id)
+        .and_then(|bindings| bindings.source_location.as_ref())
+        .map(|source_location| source_location.display().0)
+        .unwrap_or_default()
+}
+
+fn format_trimmed_interface_list(names: &BTreeSet<String>) -> String {
+    display_names(names.iter().map(String::as_str), 1)
+        .into_iter()
+        .map(|name| format!("\"{name}\""))
+        .collect::<Vec<_>>()
+        .join(", ")
+}
+
+fn display_internal_api_interface_name(name: &str, source_file: &str) -> String {
+    display_name_from_source_path_in_context(name, source_file, std::iter::empty())
+}
+
 #[cfg(test)]
 #[path = "test/sequence_internal_api_validator_test.rs"]
 mod tests;
diff --git a/validation/core/src/validators/shared/diagram_analysis.rs b/validation/core/src/validators/shared/diagram_analysis.rs
index 06b169d4..ff13d8d9 100644
--- a/validation/core/src/validators/shared/diagram_analysis.rs
+++ b/validation/core/src/validators/shared/diagram_analysis.rs
@@ -34,8 +34,8 @@ pub(in crate::validators) struct UnitInterfaces {
 
 #[derive(Clone)]
 pub(in crate::validators) struct SequenceCallContext<'a> {
-    pub(in crate::validators) caller_unit: &'a str,
-    pub(in crate::validators) callee_unit: &'a str,
+    pub(in crate::validators) caller_unit: String,
+    pub(in crate::validators) callee_unit: String,
     pub(in crate::validators) method: &'a str,
     pub(in crate::validators) source_location: &'a SourceLocation,
     pub(in crate::validators) caller_interfaces: BTreeSet<String>,
@@ -59,13 +59,8 @@ pub(in crate::validators) fn build_unit_bindings(
         .collect();
     let mut unit_bindings = BTreeMap::new();
 
-    // `unit_set` is already merged and keyed by (alias, parent), so units
-    // sharing an alias under different parents stay distinct.
+    // `unit_set` is already merged and keyed by canonical unit and parent IDs.
     for entity in component_diagram.unit_set.values() {
-        let Some(alias) = entity.alias.clone() else {
-            continue;
-        };
-
         let mut bindings = UnitInterfaces {
             source_location: Some(entity.source_location.clone()),
             ..UnitInterfaces::default()
@@ -93,35 +88,57 @@ pub(in crate::validators) fn build_unit_bindings(
             }
         }
 
-        unit_bindings.insert(alias, bindings);
+        unit_bindings.insert(entity.id.clone(), bindings);
     }
 
     unit_bindings
 }
 
-pub(in crate::validators) fn all_interfaces_for_alias(
+pub(in crate::validators) fn all_interfaces_for_unit_id(
     unit_bindings: &UnitBindings,
-    alias: &str,
+    unit_id: &str,
 ) -> BTreeSet<String> {
     unit_bindings
-        .get(alias)
+        .get(unit_id)
         .map(|bindings| bindings.all_interfaces.clone())
         .unwrap_or_default()
 }
 
 pub(in crate::validators) fn build_observed_call_contexts<'a>(
     observed_calls: &'a [ObservedSequenceCall],
+    participants: &BTreeMap<String, crate::models::SequenceParticipantInfo>,
     unit_bindings: &UnitBindings,
 ) -> Vec<SequenceCallContext<'a>> {
+    // Sequence interactions reference participants by sender/receiver names,
+    // so validators need a declaration bridge from those reference names back
+    // to the canonical participant uid used as the participant map key.
+    let mut participant_uids_by_reference_name: BTreeMap<&str, BTreeSet<&str>> = BTreeMap::new();
+    for (participant_uid, participant_info) in participants {
+        participant_uids_by_reference_name
+            .entry(participant_info.reference_name.as_str())
+            .or_default()
+            .insert(participant_uid.as_str());
+    }
+
     observed_calls
         .iter()
         .map(|call| {
-            let caller_interfaces = all_interfaces_for_alias(unit_bindings, &call.caller);
-            let callee_interfaces = all_interfaces_for_alias(unit_bindings, &call.callee);
+            let caller_unit = resolve_observed_call_unit_id(
+                unit_bindings,
+                &participant_uids_by_reference_name,
+                &call.caller,
+            );
+            let callee_unit = resolve_observed_call_unit_id(
+                unit_bindings,
+                &participant_uids_by_reference_name,
+                &call.callee,
+            );
+            let caller_interfaces = all_interfaces_for_unit_id(unit_bindings, &caller_unit);
+            let callee_interfaces = all_interfaces_for_unit_id(unit_bindings, &callee_unit);
 
             SequenceCallContext {
-                caller_unit: call.caller.as_str(),
-                callee_unit: call.callee.as_str(),
+                caller_unit,
+                callee_unit,
                 method: call.method.as_str(),
                 caller_interfaces,
                 callee_interfaces,
@@ -131,6 +148,28 @@ pub(in crate::validators) fn build_observed_call_contexts<'a>(
         .collect()
 }
 
+pub(in crate::validators) fn resolve_observed_call_unit_id(
+    unit_bindings: &UnitBindings,
+    participant_uids_by_reference_name: &BTreeMap<&str, BTreeSet<&str>>,
+    observed_unit: &str,
+) -> String {
+    if unit_bindings.contains_key(observed_unit) {
+        return observed_unit.to_string();
+    }
+
+    if let Some(participant_uids) = participant_uids_by_reference_name.get(observed_unit) {
+        if participant_uids.len() == 1 {
+            return participant_uids
+                .iter()
+                .next()
+                .expect("participant UID set length was checked")
+                .to_string();
+        }
+    }
+
+    observed_unit.to_string()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -169,7 +208,7 @@ mod tests {
     }
 
     #[test]
-    fn units_sharing_an_alias_under_different_parents_are_not_merged() {
+    fn units_sharing_an_alias_under_different_parents_keep_distinct_id_bindings() {
         let entities = vec![
             entity(
                 "comp_a",
@@ -233,13 +272,13 @@ mod tests {
         assert_eq!(architecture.unit_set.len(), 2);
 
         let bindings = build_unit_bindings(&architecture);
-        let unit_x = bindings.get("unit_x").expect("expected a unit_x entry");
-        // Bare-alias collision resolves to one entry; it must reflect only one unit's interfaces.
-        assert!(
-            unit_x.all_interfaces == BTreeSet::from(["iface_a".to_string()])
-                || unit_x.all_interfaces == BTreeSet::from(["iface_b".to_string()]),
-            "expected exactly one unit's interfaces, got {:?}",
-            unit_x.all_interfaces
+        assert_eq!(
+            bindings["comp_a.unit_x"].all_interfaces,
+            BTreeSet::from(["iface_a".to_string()])
+        );
+        assert_eq!(
+            bindings["comp_b.unit_x"].all_interfaces,
+            BTreeSet::from(["iface_b".to_string()])
         );
     }
 }
diff --git a/validation/core/src/validators/shared/display.rs b/validation/core/src/validators/shared/display.rs
new file mode 100644
index 00000000..e0051c54
--- /dev/null
+++ b/validation/core/src/validators/shared/display.rs
@@ -0,0 +1,525 @@
+// *******************************************************************************
+// Copyright (c) 2026 Contributors to the Eclipse Foundation
+//
+// See the NOTICE file(s) distributed with this work for additional
+// information regarding copyright ownership.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Apache License Version 2.0 which is available at
+// <https://www.apache.org/licenses/LICENSE-2.0>
+//
+// SPDX-License-Identifier: Apache-2.0
+// *******************************************************************************
+
+use std::collections::{BTreeMap, BTreeSet};
+use std::path::{Component, Path};
+
+use class_diagram::{Relationship, SimpleEntity};
+use source_location::SourceLocation;
+use uid_utils::{join, normalized_segments};
+
+pub(crate) fn display_reference_name(reference: &str) -> &str {
+    let trimmed = reference.trim();
+
+    trimmed
+        .rsplit(['.', ':'])
+        .find(|segment| !segment.is_empty())
+        .unwrap_or(trimmed)
+}
+
+pub(crate) fn display_entity_name(entity: &SimpleEntity) -> &str {
+    if entity.name.trim().is_empty() {
+        display_reference_name(&entity.id)
+    } else {
+        entity.name.as_str()
+    }
+}
+
+pub(crate) fn display_relationship_name(relationship: &Relationship) -> String {
+    format!(
+        "{} -> {:?} -> {}",
+        display_reference_name(&relationship.source),
+        relationship.relation_type,
+        display_reference_name(&relationship.target)
+    )
+}
+
+pub(crate) fn display_names<'a>(
+    names: impl IntoIterator<Item = &'a str>,
+    min_segments: usize,
+) -> Vec<String> {
+    let segmented = names
+        .into_iter()
+        .map(normalized_segments)
+        .collect::<Vec<_>>();
+
+    segmented
+        .iter()
+        .enumerate()
+        .map(|(index, target_segments)| {
+            let min_suffix_length = min_segments.min(target_segments.len());
+            let suffix_length = (1..=target_segments.len())
+                .find(|length| {
+                    let target_suffix = &target_segments[target_segments.len() - length..];
+
+                    segmented
+                        .iter()
+                        .enumerate()
+                        .all(|(other_index, other_segments)| {
+                            other_index == index
+                                || other_segments.len() < *length
+                                || &other_segments[other_segments.len() - length..] != target_suffix
+                        })
+                })
+                .map(|length| length.max(min_suffix_length))
+                .unwrap_or(min_suffix_length);
+
+            join(
+                target_segments[target_segments.len() - suffix_length..]
+                    .iter()
+                    .map(String::as_str),
+            )
+        })
+        .collect()
+}
+
+pub(crate) fn display_names_without_common_prefix<'a>(
+    names: impl IntoIterator<Item = &'a str>,
+    min_segments: usize,
+) -> Vec<String> {
+    let segmented = names
+        .into_iter()
+        .map(normalized_segments)
+        .collect::<Vec<_>>();
+    let min_segments = if segmented.iter().all(|segments| segments.len() <= 4) {
+        min_segments.min(2)
+    } else {
+        min_segments
+    };
+    let shared_prefix_len = common_prefix_len(&segmented);
+
+    let trimmed = segmented
+        .iter()
+        .map(|segments| {
+            let min_segments = min_segments.min(segments.len());
+            let removable = segments.len().saturating_sub(min_segments);
+            let remove_count = shared_prefix_len.min(removable);
+            join(segments[remove_count..].iter().map(String::as_str))
+        })
+        .collect::<Vec<_>>();
+
+    display_names(trimmed.iter().map(String::as_str), min_segments)
+}
+
+pub(crate) fn display_name_from_source_path(
+    name: &str,
+    source_file: &str,
+    min_segments: usize,
+) -> String {
+    strip_source_path_prefix(name, source_file, min_segments).unwrap_or_else(|| {
+        display_names_without_common_prefix([name], min_segments)
+            .into_iter()
+            .next()
+            .unwrap_or_else(|| name.to_string())
+    })
+}
+
+pub(in crate::validators) fn display_name_from_source_path_in_context<'a>(
+    target: &'a str,
+    source_file: &str,
+    other_names: impl IntoIterator<Item = &'a str>,
+) -> String {
+    let other_names = other_names.into_iter().collect::<Vec<_>>();
+    let source_display = display_name_from_source_path(target, source_file, 1);
+    let context_names = std::iter::once(target)
+        .chain(other_names.iter().copied())
+        .collect::<Vec<_>>();
+    let context_display = display_names(context_names, 1);
+
+    let source_segments = normalized_segments(&source_display);
+    let source_display_is_unique = other_names.iter().all(|other_name| {
+        let other_segments = normalized_segments(other_name);
+        if other_segments.len() < source_segments.len() {
+            true
+        } else {
+            other_segments[other_segments.len() - source_segments.len()..] != source_segments[..]
+        }
+    });
+
+    if source_display_is_unique {
+        source_display
+    } else {
+        context_display
+            .into_iter()
+            .next()
+            .unwrap_or_else(|| target.to_string())
+    }
+}
+
+pub(in crate::validators) fn display_name_from_sources(
+    name: &str,
+    sources: &BTreeMap<String, SourceLocation>,
+) -> String {
+    let source_file = sources
+        .get(name)
+        .map(|source_location| source_location.display().0);
+
+    display_name_from_source_path_in_context(name, source_file.as_deref().unwrap_or_default(), [])
+}
+
+pub(in crate::validators) fn display_names_from_sources(
+    names: &BTreeSet<String>,
+    sources: &BTreeMap<String, SourceLocation>,
+) -> BTreeSet<String> {
+    names
+        .iter()
+        .map(|name| display_name_from_sources(name, sources))
+        .collect()
+}
+
+pub(in crate::validators) fn display_unit_pair_from_source_paths(
+    left: &str,
+    left_source_file: &str,
+    right: &str,
+    right_source_file: &str,
+) -> [String; 2] {
+    let displayed = [
+        display_name_from_source_path(left, left_source_file, unit_min_segments(left)),
+        display_name_from_source_path(right, right_source_file, unit_min_segments(right)),
+    ];
+
+    if displayed[0] == displayed[1] {
+        display_unit_pair(left, right)
+    } else {
+        displayed
+    }
+}
+
+pub(in crate::validators) fn display_unit_pair_from_optional_source_paths(
+    left: &str,
+    left_source_file: Option<&str>,
+    right: &str,
+    right_source_file: Option<&str>,
+) -> [String; 2] {
+    match (left_source_file, right_source_file) {
+        (Some(left_source_file), Some(right_source_file))
+            if !left_source_file.is_empty() && !right_source_file.is_empty() =>
+        {
+            display_unit_pair_from_source_paths(left, left_source_file, right, right_source_file)
+        }
+        _ => display_unit_pair(left, right),
+    }
+}
+
+pub(crate) fn format_display_names<'a>(
+    names: impl IntoIterator<Item = &'a str>,
+    min_segments: usize,
+) -> String {
+    let displayed = display_names_without_common_prefix(names, min_segments);
+
+    if displayed.is_empty() {
+        return "<none>".to_string();
+    }
+
+    displayed
+        .into_iter()
+        .map(|name| format!("\"{name}\""))
+        .collect::<Vec<_>>()
+        .join(", ")
+}
+
+fn common_prefix_len(segmented_names: &[Vec<String>]) -> usize {
+    let Some(first) = segmented_names.first() else {
+        return 0;
+    };
+
+    first
+        .iter()
+        .enumerate()
+        .take_while(|(index, segment)| {
+            segmented_names
+                .iter()
+                .all(|segments| segments.get(*index) == Some(segment))
+        })
+        .count()
+}
+
+fn strip_source_path_prefix(name: &str, source_file: &str, min_segments: usize) -> Option<String> {
+    let name_segments = normalized_segments(name);
+    if name_segments.is_empty() {
+        return None;
+    }
+
+    let source_segments = source_directory_segments(source_file);
+    let overlap_len = longest_suffix_prefix_overlap(&source_segments, &name_segments);
+    if overlap_len == 0 {
+        return None;
+    }
+
+    let min_segments = min_segments.min(name_segments.len());
+    let removable = name_segments.len().saturating_sub(min_segments);
+    let remove_count = overlap_len.min(removable);
+
+    Some(join(
+        name_segments[remove_count..].iter().map(String::as_str),
+    ))
+}
+
+fn source_directory_segments(source_file: &str) -> Vec<String> {
+    Path::new(source_file)
+        .parent()
+        .into_iter()
+        .flat_map(Path::components)
+        .filter_map(|component| match component {
+            Component::Normal(segment) => Some(segment.to_string_lossy().to_string()),
+            _ => None,
+        })
+        .collect()
+}
+
+fn longest_suffix_prefix_overlap(source_segments: &[String], name_segments: &[String]) -> usize {
+    let max_overlap = source_segments.len().min(name_segments.len());
+
+    (1..=max_overlap)
+        .rev()
+        .find(|overlap_len| {
+            source_segments[source_segments.len() - overlap_len..] == name_segments[..*overlap_len]
+        })
+        .unwrap_or(0)
+}
+
+pub(in crate::validators) fn display_reference_name_set(
+    names: &BTreeSet<String>,
+) -> BTreeSet<String> {
+    names
+        .iter()
+        .map(|name| display_reference_name(name).to_string())
+        .collect()
+}
+
+pub(in crate::validators) fn display_unit_pair(left: &str, right: &str) -> [String; 2] {
+    let names = [left, right];
+    let min_segments = if names
+        .iter()
+        .map(|name| normalized_segments(name).len())
+        .all(|segment_count| segment_count <= 4)
+    {
+        2
+    } else {
+        3
+    };
+    let displayed = display_names_without_common_prefix(names, min_segments);
+
+    [displayed[0].clone(), displayed[1].clone()]
+}
+
+fn unit_min_segments(name: &str) -> usize {
+    if normalized_segments(name).len() <= 4 {
+        2
+    } else {
+        3
+    }
+}
+
+pub(in crate::validators) fn format_name_list<T>(names: impl IntoIterator<Item = T>) -> String
+where
+    T: AsRef<str>,
+{
+    names
+        .into_iter()
+        .map(|name| format!("\"{}\"", name.as_ref()))
+        .collect::<Vec<_>>()
+        .join(", ")
+}
+
+pub(in crate::validators) fn format_sequence_call(
+    caller: &str,
+    callee: &str,
+    method_name: &str,
+) -> String {
+    format!("\"{caller}\" -> \"{callee}\" : \"{method_name}\"")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{
+        display_entity_name, display_name_from_source_path,
+        display_name_from_source_path_in_context, display_names,
+        display_names_without_common_prefix, display_reference_name, display_relationship_name,
+        display_unit_pair_from_source_paths, format_display_names,
+    };
+    use class_diagram::{EntityType, RelationType, Relationship, SimpleEntity};
+    use source_location::SourceLocation;
+
+    #[test]
+    fn display_reference_name_uses_leaf_for_root_anchored_identifiers() {
+        assert_eq!(
+            display_reference_name("validation.core.test.Engine"),
+            "Engine"
+        );
+        assert_eq!(
+            display_reference_name("validation::core::test::Engine"),
+            "Engine"
+        );
+    }
+
+    #[test]
+    fn display_entity_name_prefers_entity_name_over_id() {
+        let entity = SimpleEntity {
+            id: "validation.core.test.Engine".to_string(),
+            name: "Engine".to_string(),
+            enclosing_namespace_id: None,
+            stereotypes: Vec::new(),
+            entity_type: EntityType::Class,
+            type_aliases: Vec::new(),
+            variables: Vec::new(),
+            methods: Vec::new(),
+            template_parameters: None,
+            enum_literals: Vec::new(),
+            relationships: Vec::new(),
+            source_location: SourceLocation::new("test.puml", 1),
+        };
+
+        assert_eq!(display_entity_name(&entity), "Engine");
+    }
+
+    #[test]
+    fn display_relationship_name_uses_short_endpoint_names() {
+        let relationship = Relationship {
+            source: "validation.core.test.Car".to_string(),
+            target: "validation::core::test::Wheel".to_string(),
+            relation_type: RelationType::Composition,
+            source_multiplicity: None,
+            target_multiplicity: None,
+            source_location: SourceLocation::new("test.puml", 1),
+        };
+
+        assert_eq!(
+            display_relationship_name(&relationship),
+            "Car -> Composition -> Wheel"
+        );
+    }
+
+    #[test]
+    fn display_names_uses_shortest_unique_suffix() {
+        let names = [
+            "validation.core.example.unit_1.Controller",
+            "validation.core.example.unit_2.Controller",
+        ];
+
+        assert_eq!(
+            display_names(names, 1),
+            vec!["unit_1.Controller", "unit_2.Controller"]
+        );
+    }
+
+    #[test]
+    fn display_names_keeps_leaf_when_already_unique() {
+        let names = [
+            "validation.core.example.Repository",
+            "validation.core.example.Service",
+        ];
+
+        assert_eq!(display_names(names, 1), vec!["Repository", "Service"]);
+    }
+
+    #[test]
+    fn display_name_from_source_path_expands_when_context_has_same_display_name() {
+        assert_eq!(
+            display_name_from_source_path_in_context(
+                "validation.core.vehicle.control.SensorUnit",
+                "validation/core/vehicle/component.puml",
+                ["control.SensorUnit"],
+            ),
+            "vehicle.control.SensorUnit"
+        );
+    }
+
+    #[test]
+    fn display_names_shortens_single_name() {
+        assert_eq!(
+            display_names(
+                ["validation.core.integration_test.component_sequence.case_a.package_a.InternalInterface"],
+                2,
+            ),
+            vec!["package_a.InternalInterface"]
+        );
+    }
+
+    #[test]
+    fn format_display_names_quotes_names() {
+        let names = [
+            "validation.core.integration_test.case_a.package_a.InternalInterface",
+            "validation.core.integration_test.case_a.package_b.InternalInterface",
+        ];
+
+        assert_eq!(
+            format_display_names(names, 2),
+            "\"package_a.InternalInterface\", \"package_b.InternalInterface\""
+        );
+    }
+
+    #[test]
+    fn format_display_names_handles_empty() {
+        assert_eq!(
+            format_display_names(std::iter::empty::<&str>(), 2),
+            "<none>"
+        );
+    }
+
+    #[test]
+    fn display_names_without_common_prefix_caps_short_names_at_two_segments() {
+        let names = [
+            "validation.core.integration_test.case_a.package_a.component_a.unit_1",
+            "validation.core.integration_test.case_a.package_b.component_a.unit_1",
+        ];
+
+        assert_eq!(
+            display_names_without_common_prefix(names, 3),
+            vec![
+                "package_a.component_a.unit_1",
+                "package_b.component_a.unit_1"
+            ]
+        );
+    }
+
+    #[test]
+    fn display_name_from_source_path_drops_matching_directory_prefix() {
+        assert_eq!(
+            display_name_from_source_path(
+                "validation.core.integration_test.case_a.package_a.InternalInterface",
+                "validation/core/integration_test/case_a/component_diagram.puml",
+                2,
+            ),
+            "package_a.InternalInterface"
+        );
+    }
+
+    #[test]
+    fn display_name_from_source_path_falls_back_without_overlap() {
+        assert_eq!(
+            display_name_from_source_path(
+                "validation.core.integration_test.case_a.package_a.component_a.unit_1",
+                "other/root/component_diagram.puml",
+                3,
+            ),
+            "package_a.component_a.unit_1"
+        );
+    }
+
+    #[test]
+    fn display_unit_pair_from_source_paths_uses_distinct_trimmed_names() {
+        assert_eq!(
+            display_unit_pair_from_source_paths(
+                "validation.core.case_a.package_a.component_a.Controller",
+                "validation/core/case_a/component_diagram_a.puml",
+                "validation.core.case_b.package_b.component_b.Controller",
+                "validation/core/case_b/component_diagram_b.puml",
+            ),
+            [
+                "package_a.component_a.Controller".to_string(),
+                "package_b.component_b.Controller".to_string(),
+            ]
+        );
+    }
+}
diff --git a/validation/core/src/validators/shared/helpers.rs b/validation/core/src/validators/shared/helpers.rs
index d2f49644..5a732643 100644
--- a/validation/core/src/validators/shared/helpers.rs
+++ b/validation/core/src/validators/shared/helpers.rs
@@ -20,18 +20,6 @@ use strsim::jaro_winkler;
 
 pub(in crate::validators) const DEFAULT_SUGGESTION_THRESHOLD: f64 = 0.75;
 
-pub(in crate::validators) fn format_name_list(names: &BTreeSet<String>) -> String {
-    if names.is_empty() {
-        return "<none>".to_string();
-    }
-
-    names
-        .iter()
-        .map(|name| format!("\"{name}\""))
-        .collect::<Vec<_>>()
-        .join(", ")
-}
-
 /// Reduces `(id, source_location)` pairs to one entry per `id`, keeping the
 /// earliest location (by file, then line) so the result doesn't depend on
 /// iteration order.
@@ -52,14 +40,6 @@ pub(in crate::validators) fn earliest_source_by_id(
     result
 }
 
-pub(in crate::validators) fn format_sequence_call(
-    caller_unit: &str,
-    callee_unit: &str,
-    method_name: &str,
-) -> String {
-    format!("\"{caller_unit}\" -> \"{callee_unit}\" : \"{method_name}\"")
-}
-
 pub(in crate::validators) fn extract_method_name(method: &str) -> &str {
     method.split('(').next().unwrap_or(method).trim()
 }
diff --git a/validation/core/src/validators/shared/mod.rs b/validation/core/src/validators/shared/mod.rs
index c0c5ab82..1e84f270 100644
--- a/validation/core/src/validators/shared/mod.rs
+++ b/validation/core/src/validators/shared/mod.rs
@@ -14,13 +14,22 @@
 //! Shared validator analysis and helper utilities.
 
 mod diagram_analysis;
+mod display;
 mod helpers;
 
 pub(in crate::validators) use diagram_analysis::{
     build_observed_call_contexts, build_unit_bindings, SequenceCallContext, UnitBindings,
     UnitInterfaces,
 };
+pub(crate) use display::display_name_from_source_path;
+pub(crate) use display::{display_entity_name, display_reference_name, display_relationship_name};
+pub(in crate::validators) use display::{
+    display_name_from_source_path_in_context, display_name_from_sources, display_names,
+    display_names_from_sources, display_names_without_common_prefix, display_reference_name_set,
+    display_unit_pair_from_optional_source_paths, format_display_names, format_name_list,
+    format_sequence_call,
+};
 pub(in crate::validators) use helpers::{
-    best_string_suggestion, earliest_source_by_id, extract_method_name, format_name_list,
-    format_sequence_call, intersect_interfaces,
+    best_string_suggestion, earliest_source_by_id, extract_method_name, intersect_interfaces,
 };
+pub(crate) use uid_utils::normalize;
diff --git a/validation/core/src/validators/test/class_design_sequence_validator_test.rs b/validation/core/src/validators/test/class_design_sequence_validator_test.rs
index 9bb52a2f..4e2d8bb0 100644
--- a/validation/core/src/validators/test/class_design_sequence_validator_test.rs
+++ b/validation/core/src/validators/test/class_design_sequence_validator_test.rs
@@ -42,9 +42,10 @@ fn class_diagrams(entities: Vec<class_diagram::SimpleEntity>) -> ClassDiagramInp
 }
 
 fn class_entity(id: &str, namespace: Option<&str>) -> class_diagram::SimpleEntity {
-    let mut entity = class_interface(id, namespace);
-    entity.entity_type = class_diagram::EntityType::Class;
-    entity
+    let entity_id = namespace
+        .map(|namespace| format!("{namespace}.{id}"))
+        .unwrap_or_else(|| id.to_string());
+    class_entity_with_fields(&entity_id, id, namespace)
 }
 
 #[test]
@@ -86,9 +87,43 @@ fn reports_sequence_participant_missing_with_fuzzy_class_suggestion() {
         .contains("Suggestion for \"Repositry\" : Did you mean class \"Repository\"?"));
 }
 
+#[test]
+fn reports_short_participant_name_for_missing_fully_qualified_class_id() {
+    let design_classes = class_diagrams(vec![class_entity("Repository", None)]);
+    let sequence_diagrams = sequence_diagrams(&["validation.core.example.Repositry"]);
+
+    let validation_result = validate(design_classes, sequence_diagrams);
+
+    assert_eq!(validation_result.failures.len(), 1);
+    assert!(validation_result.failures[0].contains(
+        "[Class] Sequence participant \"Repositry\" has no matching class in the class diagram."
+    ));
+    assert!(validation_result.failures[0]
+        .contains("Suggestion for \"Repositry\" : Did you mean class \"Repository\"?"));
+}
+
+#[test]
+fn suggests_namespaced_class_id_for_short_participant_name() {
+    let design_classes = class_diagrams(vec![class_entity("Repository", Some("A"))]);
+    let sequence_diagrams = sequence_diagrams(&["Repository"]);
+
+    let validation_result = validate(design_classes, sequence_diagrams);
+
+    assert_eq!(validation_result.failures.len(), 1);
+    assert!(validation_result.failures[0]
+        .contains("Suggestion for \"Repository\" : Did you mean class \"A.Repository\"?"));
+    assert!(
+        validation_result.failures[0].contains("Add class \"A.Repository\" to the class diagram")
+    );
+}
+
 #[test]
 fn matches_sequence_participant_against_fully_qualified_class_id() {
-    let design_classes = class_diagrams(vec![class_entity("Controller", Some("unit_1"))]);
+    let design_classes = class_diagrams(vec![class_entity_with_fields(
+        "unit_1.Controller",
+        "DisplayedController",
+        Some("unit_1"),
+    )]);
     let sequence_diagrams = sequence_diagrams(&["unit_1::Controller"]);
 
     let validation_result = validate(design_classes, sequence_diagrams);
@@ -97,31 +132,36 @@ fn matches_sequence_participant_against_fully_qualified_class_id() {
 }
 
 #[test]
-fn matches_sequence_participant_against_unique_short_name() {
+fn reports_sequence_participant_missing_when_only_short_name_is_provided() {
     let design_classes = class_diagrams(vec![class_entity("Controller", Some("unit_1"))]);
     let sequence_diagrams = sequence_diagrams(&["Controller"]);
 
     let validation_result = validate(design_classes, sequence_diagrams);
 
-    assert!(validation_result.failures.is_empty());
+    assert_eq!(validation_result.failures.len(), 1);
+    assert!(validation_result.failures[0].contains(
+        "[Class] Sequence participant \"Controller\" has no matching class in the class diagram."
+    ));
 }
 
 #[test]
-fn reports_sequence_participant_with_ambiguous_short_name() {
-    let design_classes = class_diagrams(vec![
-        class_entity("Controller", Some("unit_1")),
-        class_entity("Controller", Some("unit_2")),
-    ]);
-    let sequence_diagrams = sequence_diagrams(&["Controller"]);
+fn reports_invalid_participant_identifier_when_sequence_participant_is_not_class_like() {
+    let design_classes = class_diagrams(vec![class_entity("Process", None)]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![sequence_participant_with_fields(
+            "Process/nara.com user",
+            Some("help"),
+            ":Process/nara::com user",
+        )],
+        &[("help", "help", "Execute()")],
+    );
 
     let validation_result = validate(design_classes, sequence_diagrams);
+    let failure = &validation_result.failures[0];
 
     assert_eq!(validation_result.failures.len(), 1);
-    assert!(validation_result.failures[0].contains(
-        "[Class] Sequence participant \"Controller\" matches multiple classes in the class diagram."
-    ));
-    assert!(validation_result.failures[0].contains("\"unit_1.Controller\""));
-    assert!(validation_result.failures[0].contains("\"unit_2.Controller\""));
+    assert!(failure.contains("valid class identifier"));
+    assert!(failure.contains("participant uid"));
 }
 
 #[test]
@@ -193,29 +233,6 @@ fn passes_when_sequence_self_call_targets_existing_method() {
     assert!(validation_result.failures.is_empty());
 }
 
-#[test]
-fn extracts_ignored_special_display_suffix() {
-    let mut sequence_diagrams = sequence_diagrams(&["help"]);
-    sequence_diagrams.diagrams[0].participants[0].display_name =
-        ":Process/nara::com user".to_string();
-    sequence_diagrams.diagrams[0].participants[0].alias = Some("help".to_string());
-
-    let mut setup_result = ValidationResult::default();
-    let sequence_index = sequence_diagrams.to_sequence_diagram_index(&mut setup_result);
-    assert!(
-        setup_result.is_empty(),
-        "test fixture setup failed: {:?}",
-        setup_result.failures
-    );
-
-    let participant_info = sequence_index.participant_info("help").unwrap();
-
-    assert_eq!(
-        ignored_special_display_suffix(participant_info),
-        Some("ara::com user".to_string())
-    );
-}
-
 fn relationship(source: &str, target: &str, relation_type: RelationType) -> Relationship {
     Relationship {
         source: source.to_string(),
diff --git a/validation/core/src/validators/test/component_internal_api_validator_test.rs b/validation/core/src/validators/test/component_internal_api_validator_test.rs
index 060833d5..6bf6a6f5 100644
--- a/validation/core/src/validators/test/component_internal_api_validator_test.rs
+++ b/validation/core/src/validators/test/component_internal_api_validator_test.rs
@@ -42,7 +42,7 @@ fn reports_missing_component_interface_declared_by_internal_api() {
 
     assert_eq!(validation_result.failures.len(), 1);
     assert!(validation_result.failures[0].contains(
-        "Component interface(s) \"component_example.InternalInterface\" from the component diagram not found in the internal API diagram."
+        "Component interface(s) \"InternalInterface\" from the component diagram not found in the internal API diagram."
     ));
     assert!(!validation_result.failures[0].contains("Unit                :"));
 }
@@ -55,17 +55,12 @@ fn reports_each_missing_component_interface_once() {
         interface_with_parent_id("InternalInterface", "component_example"),
         interface_with_parent_id("InternalInterface1", "component_example"),
     ]);
-    let internal_api = internal_api_index(vec![(
-        "component_example.InternalInterface",
-        vec!["GetData"],
-    )]);
+    let internal_api = internal_api_index(vec![("InternalInterface", vec!["GetData"])]);
 
     let validation_result = validate(component_diagrams, &internal_api);
 
     assert_eq!(validation_result.failures.len(), 1);
-    assert!(validation_result.failures[0].contains(
-        "Component interface(s) \"component_example.InternalInterface1\" from the component diagram not found in the internal API diagram."
-    ));
+    assert!(validation_result.failures[0].contains("\"InternalInterface1\""));
 }
 
 #[test]
@@ -80,7 +75,7 @@ fn reports_missing_component_interface_even_without_unit_relation() {
 
     assert_eq!(validation_result.failures.len(), 1);
     assert!(validation_result.failures[0].contains(
-        "Component interface(s) \"component_example.UnusedInterface\" from the component diagram not found in the internal API diagram."
+        "Component interface(s) \"UnusedInterface\" from the component diagram not found in the internal API diagram."
     ));
 }
 
@@ -93,17 +88,12 @@ fn reports_all_missing_component_interfaces_in_one_message() {
         interface_with_parent_id("InternalInterface", "component_example"),
         interface_with_parent_id("InternalInterface1", "component_example"),
     ]);
-    let internal_api = internal_api_index(vec![(
-        "component_example.InternalInterface",
-        vec!["GetData"],
-    )]);
+    let internal_api = internal_api_index(vec![("InternalInterface", vec!["GetData"])]);
 
     let validation_result = validate(component_diagrams, &internal_api);
 
     assert_eq!(validation_result.failures.len(), 1);
-    assert!(validation_result.failures[0].contains(
-        "Component interface(s) \"component_example.InternalInterface1\" from the component diagram not found in the internal API diagram."
-    ));
+    assert!(validation_result.failures[0].contains("\"InternalInterface1\""));
 }
 
 #[test]
@@ -118,7 +108,7 @@ fn reports_missing_component_interface_without_sequence_method_call() {
 
     assert_eq!(validation_result.failures.len(), 1);
     assert!(validation_result.failures[0].contains(
-        "Component interface(s) \"component_example.InternalInterface\" from the component diagram not found in the internal API diagram."
+        "Component interface(s) \"InternalInterface\" from the component diagram not found in the internal API diagram."
     ));
 }
 
@@ -135,12 +125,12 @@ fn reports_case_mismatch_between_component_and_internal_api_interface_names() {
 
     assert_eq!(validation_result.failures.len(), 1);
     assert!(validation_result.failures[0].contains(
-        "Component interface(s) \"component_example.InternalInterface\" from the component diagram not found in the internal API diagram."
+        "Component interface(s) \"InternalInterface\" from the component diagram not found in the internal API diagram."
     ));
 }
 
 #[test]
-fn matches_internal_api_by_component_interface_id_when_alias_differs() {
+fn matches_internal_api_by_component_interface_id_when_interface_reference_format_differs() {
     let component_diagrams = component_diagram(vec![
         unit("u1", &["pkg.InternalInterface"], &[]),
         unit("u2", &["pkg.InternalInterface"], &[]),
diff --git a/validation/core/src/validators/test/component_public_api_validator_test.rs b/validation/core/src/validators/test/component_public_api_validator_test.rs
index 8c7a9504..503f17a5 100644
--- a/validation/core/src/validators/test/component_public_api_validator_test.rs
+++ b/validation/core/src/validators/test/component_public_api_validator_test.rs
@@ -68,7 +68,7 @@ fn passes_when_top_level_public_api_is_declared_and_related_from_seooc() {
         seooc_with_public_api_relations("sample_seooc", &["SampleLibraryAPI"]),
         interface("SampleLibraryAPI"),
     ]);
-    let public_api = public_api_index(vec![("SampleLibraryAPI", Some("sample_seooc"))]);
+    let public_api = public_api_index(vec![("SampleLibraryAPI", None)]);
 
     let validation_result = validate(component_diagrams, &public_api);
 
@@ -97,7 +97,7 @@ fn reports_public_api_without_seooc_relationship() {
         seooc_with_public_api_relations("sample_seooc", &[]),
         interface("SampleLibraryAPI"),
     ]);
-    let public_api = public_api_index(vec![("SampleLibraryAPI", Some("sample_seooc"))]);
+    let public_api = public_api_index(vec![("SampleLibraryAPI", None)]);
 
     let validation_result = validate(component_diagrams, &public_api);
 
@@ -123,7 +123,7 @@ fn ignores_component_relationships_when_checking_public_api() {
         component,
         interface("SampleLibraryAPI"),
     ]);
-    let public_api = public_api_index(vec![("SampleLibraryAPI", Some("component_example"))]);
+    let public_api = public_api_index(vec![("SampleLibraryAPI", None)]);
 
     let validation_result = validate(component_diagrams, &public_api);
 
@@ -134,6 +134,22 @@ fn ignores_component_relationships_when_checking_public_api() {
     assert!(validation_result.failures[0].contains("\"SampleLibraryAPI\""));
 }
 
+#[test]
+fn reports_missing_when_only_namespaced_public_api_id_exists() {
+    let component_diagrams = component_diagram(vec![
+        seooc_with_public_api_relations("sample_seooc", &["SampleLibraryAPI"]),
+        interface("SampleLibraryAPI"),
+    ]);
+    let public_api = public_api_index(vec![("SampleLibraryAPI", Some("sample_seooc"))]);
+
+    let validation_result = validate(component_diagrams, &public_api);
+
+    assert_eq!(validation_result.failures.len(), 1);
+    assert!(validation_result.failures[0].contains(
+        "[Interface] Public API interface(s) \"SampleLibraryAPI\" from the static diagram not found in the public API diagram."
+    ));
+}
+
 #[test]
 fn ignores_internal_interface_bindings_when_checking_public_api() {
     let component_diagrams = component_diagram(vec![
diff --git a/validation/core/src/validators/test/component_sequence_validator_test.rs b/validation/core/src/validators/test/component_sequence_validator_test.rs
index f3b4e023..eff5a845 100644
--- a/validation/core/src/validators/test/component_sequence_validator_test.rs
+++ b/validation/core/src/validators/test/component_sequence_validator_test.rs
@@ -12,7 +12,7 @@
 // *******************************************************************************
 use super::super::fixtures::*;
 use super::*;
-use crate::models::{ComponentDiagramInputs, ComponentType, LogicComponent, SequenceDiagramInputs};
+use crate::models::{ComponentDiagramInputs, SequenceDiagramInputs};
 use crate::ValidationResult;
 
 fn validate(
@@ -28,7 +28,7 @@ fn validate(
 }
 
 #[test]
-fn passes_when_aliases_and_participants_are_identical() {
+fn passes_when_participant_uids_match_component_unit_ids() {
     let component_diagrams = component_diagram(vec![
         unit_without_interfaces("unit_1"),
         unit_without_interfaces("unit_2"),
@@ -56,7 +56,11 @@ fn reports_missing_and_extra() {
     let missing_count = validation_result
         .failures
         .iter()
-        .filter(|msg| msg.contains("from the component diagram not found in the sequence diagram"))
+        .filter(|msg| {
+            msg.contains(
+                "from the component diagram not found as a participant uid in the sequence diagram",
+            )
+        })
         .count();
     let unexpected_count = validation_result
         .failures
@@ -69,27 +73,17 @@ fn reports_missing_and_extra() {
 }
 
 #[test]
-fn units_without_alias_are_ignored() {
-    let component_diagrams = ComponentDiagramInputs {
-        entities: vec![LogicComponent {
-            id: "module_a.unit_1".to_string(),
-            name: Some("unit_1".to_string()),
-            alias: None,
-            parent_id: None,
-            element_type: ComponentType::Component,
-            stereotype: Some("unit".to_string()),
-            relations: Vec::new(),
-            source_location: dummy_source_location(),
-        }],
-    };
+fn units_without_alias_are_validated_by_id() {
+    let component_diagrams = component_diagram(vec![unit_with_id("module_a.unit_1", None)]);
     let sequence_diagrams = sequence_diagrams(&[]);
 
     let validation_result = validate(component_diagrams, sequence_diagrams);
-    assert!(validation_result.is_empty());
+    assert_eq!(validation_result.failures.len(), 1);
+    assert!(validation_result.failures[0].contains("\"unit_1\""));
 }
 
 #[test]
-fn reports_alias_missing_from_participants() {
+fn reports_unit_id_missing_from_participants() {
     let component_diagrams = component_diagram(vec![
         unit_without_interfaces("u1"),
         unit_without_interfaces("u2"),
@@ -102,7 +96,7 @@ fn reports_alias_missing_from_participants() {
 }
 
 #[test]
-fn reports_participant_not_in_aliases() {
+fn reports_participant_uid_missing_from_component_diagram() {
     let component_diagrams = component_diagram(vec![unit_without_interfaces("u1")]);
     let sequence_diagrams = sequence_diagrams(&["u1", "orphan"]);
 
@@ -112,7 +106,7 @@ fn reports_participant_not_in_aliases() {
 }
 
 #[test]
-fn reports_missing_component_alias_and_interface_connection_for_sequence_call() {
+fn reports_unmatched_sequence_participant_and_missing_interface_connection_for_sequence_call() {
     let component_diagrams = component_diagram(vec![
         unit("u1", &["InternalInterface"], &[]),
         interface("InternalInterface"),
@@ -165,8 +159,9 @@ fn reports_missing_participant_and_missing_sequence_call_for_interface_connected
 
     assert_eq!(validation_result.failures.len(), 2);
     assert!(validation_result.failures.iter().any(|message| {
-        message.contains("from the component diagram not found in the sequence diagram")
-            && message.contains("\"u2\"")
+        message.contains(
+            "from the component diagram not found as a participant uid in the sequence diagram",
+        ) && message.contains("\"u2\"")
     }));
     assert!(validation_result.failures.iter().any(|message| {
         message.contains("have no corresponding function-call in the sequence diagram")
@@ -205,3 +200,135 @@ fn passes_when_interface_connected_units_have_sequence_call() {
     let validation_result = validate(component_diagrams, sequence_diagrams);
     assert!(validation_result.is_empty());
 }
+
+#[test]
+fn passes_when_participant_uid_matches_component_id_but_reference_names_differ() {
+    let component_diagrams = component_diagram(vec![
+        unit_with_fields(
+            "validation.core.example.unit_1",
+            Some("u1"),
+            Some("Component Unit One"),
+            None,
+            &["InternalInterface"],
+            &[],
+        ),
+        unit_with_fields(
+            "validation.core.example.unit_2",
+            Some("u2"),
+            Some("Component Unit Two"),
+            None,
+            &[],
+            &["InternalInterface"],
+        ),
+        interface("InternalInterface"),
+    ]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![
+            sequence_participant_with_fields(
+                "validation.core.example.unit_1",
+                Some("participant_a"),
+                "Unit One",
+            ),
+            sequence_participant_with_fields(
+                "validation.core.example.unit_2",
+                Some("participant_b"),
+                "Unit Two",
+            ),
+        ],
+        &[("participant_a", "participant_b", "GetData()")],
+    );
+
+    let validation_result = validate(component_diagrams, sequence_diagrams);
+    assert!(validation_result.is_empty());
+}
+
+#[test]
+fn reports_uid_mismatch_even_when_alias_and_display_name_match_component_units() {
+    let component_diagrams = component_diagram(vec![
+        unit_with_fields(
+            "validation.core.example.unit_1",
+            Some("participant_a"),
+            Some("Component Unit One"),
+            None,
+            &[],
+            &[],
+        ),
+        unit_with_fields(
+            "validation.core.example.unit_2",
+            Some("participant_b"),
+            Some("Component Unit Two"),
+            None,
+            &[],
+            &[],
+        ),
+    ]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![
+            sequence_participant_with_fields(
+                "validation.core.example.other_unit_1",
+                Some("participant_a"),
+                "participant_a",
+            ),
+            sequence_participant_with_fields(
+                "validation.core.example.other_unit_2",
+                Some("participant_b"),
+                "participant_b",
+            ),
+        ],
+        &[],
+    );
+
+    let validation_result = validate(component_diagrams, sequence_diagrams);
+
+    assert_eq!(validation_result.failures.len(), 4);
+    let missing_component_units = validation_result
+        .failures
+        .iter()
+        .filter(|message| {
+            message.contains(
+                "from the component diagram not found as a participant uid in the sequence diagram",
+            )
+        })
+        .count();
+    let unexpected_participant_uids = validation_result
+        .failures
+        .iter()
+        .filter(|message| {
+            message.contains("from the sequence diagram not found in the component diagram")
+        })
+        .count();
+
+    assert_eq!(missing_component_units, 2);
+    assert_eq!(unexpected_participant_uids, 2);
+}
+
+#[test]
+fn reports_mismatch_when_sequence_calls_use_raw_ids_instead_of_declared_participant_reference_names(
+) {
+    let component_diagrams = component_diagram(vec![
+        unit("u1", &["InternalInterface"], &[]),
+        unit("u2", &[], &["InternalInterface"]),
+        interface("InternalInterface"),
+    ]);
+    let sequence_diagrams = sequence_calls_with_participants(
+        &["u1", "u2"],
+        &[(
+            "validation.core.example.u1",
+            "validation.core.example.u2",
+            "GetData()",
+        )],
+    );
+
+    let validation_result = validate(component_diagrams, sequence_diagrams);
+    assert_eq!(validation_result.failures.len(), 2);
+    assert!(validation_result.failures.iter().any(|message| {
+        message.contains(
+            "[Interface] Component-connected units \"u1\" and \"u2\" have no corresponding function-call in the sequence diagram."
+        )
+    }));
+    assert!(validation_result.failures.iter().any(|message| {
+        message.contains(
+            "[Interface] Sequence-connected units \"example.u1\" and \"example.u2\" have no corresponding shared interface connection in the component diagram."
+        )
+    }));
+}
diff --git a/validation/core/src/validators/test/fixtures.rs b/validation/core/src/validators/test/fixtures.rs
index a146d7f0..7fed669c 100644
--- a/validation/core/src/validators/test/fixtures.rs
+++ b/validation/core/src/validators/test/fixtures.rs
@@ -73,6 +73,30 @@ pub(super) fn unit_without_interfaces(alias: &str) -> LogicComponent {
     unit(alias, &[], &[])
 }
 
+pub(super) fn unit_with_id(id: &str, alias: Option<&str>) -> LogicComponent {
+    unit_with_fields(id, alias, alias, None, &[], &[])
+}
+
+pub(super) fn unit_with_fields(
+    id: &str,
+    alias: Option<&str>,
+    display_name: Option<&str>,
+    parent_id: Option<&str>,
+    required_interfaces: &[&str],
+    provided_interfaces: &[&str],
+) -> LogicComponent {
+    LogicComponent {
+        id: id.to_string(),
+        name: display_name.map(str::to_string),
+        alias: alias.map(str::to_string),
+        parent_id: parent_id.map(str::to_string),
+        element_type: ComponentType::Component,
+        stereotype: Some("unit".to_string()),
+        relations: interface_binding_relations(required_interfaces, provided_interfaces),
+        source_location: dummy_source_location(),
+    }
+}
+
 pub(super) fn interface(alias: &str) -> LogicComponent {
     interface_entity(alias, None)
 }
@@ -164,10 +188,95 @@ pub(super) fn sequence_calls(calls: &[(&str, &str, &str)]) -> SequenceDiagramInp
     }
 }
 
+pub(super) fn sequence_calls_with_participants(
+    participants: &[&str],
+    calls: &[(&str, &str, &str)],
+) -> SequenceDiagramInputs {
+    SequenceDiagramInputs {
+        diagrams: vec![SequenceTree {
+            name: Some("seq".to_string()),
+            participants: participants
+                .iter()
+                .map(|participant| sequence_participant(participant))
+                .collect(),
+            root: Block {
+                items: calls
+                    .iter()
+                    .map(|(caller, callee, method)| {
+                        Node::Interaction(Interaction {
+                            sender: Some((*caller).to_string().into()),
+                            receiver: Some((*callee).to_string().into()),
+                            message: Some((*method).to_string()),
+                            source_location: dummy_source_location(),
+                        })
+                    })
+                    .collect(),
+            },
+        }],
+    }
+}
+
+pub(super) fn sequence_calls_with_custom_participants(
+    participants: Vec<SequenceParticipant>,
+    calls: &[(&str, &str, &str)],
+) -> SequenceDiagramInputs {
+    SequenceDiagramInputs {
+        diagrams: vec![SequenceTree {
+            name: Some("seq".to_string()),
+            participants,
+            root: Block {
+                items: calls
+                    .iter()
+                    .map(|(caller, callee, method)| {
+                        Node::Interaction(Interaction {
+                            sender: Some((*caller).to_string().into()),
+                            receiver: Some((*callee).to_string().into()),
+                            message: Some((*method).to_string()),
+                            source_location: dummy_source_location(),
+                        })
+                    })
+                    .collect(),
+            },
+        }],
+    }
+}
+
+pub(super) fn sequence_participant_with_fields(
+    uid: &str,
+    reference_name: Option<&str>,
+    display_name: &str,
+) -> SequenceParticipant {
+    SequenceParticipant {
+        display_name: display_name.to_string(),
+        alias: reference_name.map(str::to_string),
+        uid: uid.to_string(),
+        participant_type: ParticipantType::Participant,
+        source_location: dummy_source_location(),
+        stereotype: None,
+    }
+}
+
+pub(super) fn class_interface_with_fields(
+    id: &str,
+    name: &str,
+    namespace: Option<&str>,
+) -> SimpleEntity {
+    simple_entity_with_fields(id, name, EntityType::Interface, namespace)
+}
+
+pub(super) fn class_entity_with_fields(
+    id: &str,
+    name: &str,
+    namespace: Option<&str>,
+) -> SimpleEntity {
+    simple_entity_with_fields(id, name, EntityType::Class, namespace)
+}
+
 fn sequence_participant(participant: &str) -> SequenceParticipant {
     SequenceParticipant {
         display_name: participant.to_string(),
         alias: None,
+        uid: participant.to_string(),
         participant_type: ParticipantType::Participant,
         source_location: dummy_source_location(),
         stereotype: None,
@@ -194,12 +303,17 @@ pub(super) fn internal_api_index(interfaces: Vec<(&str, Vec<&str>)>) -> Internal
 }
 
 pub(super) fn class_interface(name: &str, namespace: Option<&str>) -> SimpleEntity {
-    simple_entity(name, EntityType::Interface, namespace)
+    class_interface_with_fields(&entity_id(name, namespace), name, namespace)
 }
 
-fn simple_entity(name: &str, entity_type: EntityType, namespace: Option<&str>) -> SimpleEntity {
+fn simple_entity_with_fields(
+    id: &str,
+    name: &str,
+    entity_type: EntityType,
+    namespace: Option<&str>,
+) -> SimpleEntity {
     SimpleEntity {
-        id: entity_id(name, namespace),
+        id: id.to_string(),
         name: name.to_string(),
         enclosing_namespace_id: namespace.map(str::to_string),
         stereotypes: Vec::new(),
@@ -214,6 +328,31 @@ fn simple_entity(name: &str, entity_type: EntityType, namespace: Option<&str>) -
     }
 }
 
+fn interface_binding_relations(
+    required_interfaces: &[&str],
+    provided_interfaces: &[&str],
+) -> Vec<LogicRelation> {
+    let mut relations = Vec::new();
+
+    for target in required_interfaces {
+        relations.push(relation(
+            target,
+            ComponentRelationType::InterfaceBinding,
+            EndpointRole::Required,
+        ));
+    }
+
+    for target in provided_interfaces {
+        relations.push(relation(
+            target,
+            ComponentRelationType::InterfaceBinding,
+            EndpointRole::Provided,
+        ));
+    }
+
+    relations
+}
+
 pub(super) fn method(name: &str) -> Method {
     Method {
         name: name.to_string(),
diff --git a/validation/core/src/validators/test/sequence_internal_api_validator_test.rs b/validation/core/src/validators/test/sequence_internal_api_validator_test.rs
index a58752cd..1f08eca7 100644
--- a/validation/core/src/validators/test/sequence_internal_api_validator_test.rs
+++ b/validation/core/src/validators/test/sequence_internal_api_validator_test.rs
@@ -254,6 +254,109 @@ fn passes_when_sequence_function_exists_on_related_interface_with_component_cont
     assert!(validation_result.failures.is_empty());
 }
 
+#[test]
+fn passes_when_participant_uid_matches_component_id_but_call_uses_reference_names() {
+    let component_diagrams = component_diagram(vec![
+        unit_with_fields(
+            "validation.core.example.unit_1",
+            Some("component_alias_1"),
+            Some("Component Unit One"),
+            None,
+            &["InternalInterface"],
+            &[],
+        ),
+        unit_with_fields(
+            "validation.core.example.unit_2",
+            Some("component_alias_2"),
+            Some("Component Unit Two"),
+            None,
+            &[],
+            &["InternalInterface"],
+        ),
+        interface("InternalInterface"),
+    ]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![
+            sequence_participant_with_fields(
+                "validation.core.example.unit_1",
+                Some("participant_a"),
+                "Unit One",
+            ),
+            sequence_participant_with_fields(
+                "validation.core.example.unit_2",
+                Some("participant_b"),
+                "Unit Two",
+            ),
+        ],
+        &[("participant_a", "participant_b", "GetData()")],
+    );
+    let internal_api = internal_api_index(vec![("InternalInterface", vec!["GetData"])]);
+
+    let validation_result =
+        validate_with_component_context(component_diagrams, sequence_diagrams, &internal_api);
+
+    assert!(validation_result.failures.is_empty());
+}
+
+#[test]
+fn reports_short_but_discriminative_names_for_long_unit_and_interface_ids() {
+    let component_diagrams = component_diagram(vec![
+        unit_with_fields(
+            "validation.core.example.package_a.component_a.unit_1",
+            Some("component_alias_1"),
+            Some("Long Unit One"),
+            None,
+            &["validation.core.example.package_a.InternalInterface"],
+            &[],
+        ),
+        unit_with_fields(
+            "validation.core.example.package_a.component_a.unit_2",
+            Some("component_alias_2"),
+            Some("Long Unit Two"),
+            None,
+            &[],
+            &["validation.core.example.package_a.InternalInterface"],
+        ),
+        interface("validation.core.example.package_a.InternalInterface"),
+    ]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![
+            sequence_participant_with_fields(
+                "validation.core.example.package_a.component_a.unit_1",
+                Some("participant_a"),
+                "Unit One",
+            ),
+            sequence_participant_with_fields(
+                "validation.core.example.package_a.component_a.unit_2",
+                Some("participant_b"),
+                "Unit Two",
+            ),
+        ],
+        &[("participant_a", "participant_b", "GetData()")],
+    );
+    let internal_api = internal_api_index(vec![(
+        "validation.core.example.package_a.InternalInterface",
+        vec!["OtherMethod"],
+    )]);
+
+    let validation_result =
+        validate_with_component_context(component_diagrams, sequence_diagrams, &internal_api);
+
+    assert_eq!(validation_result.failures.len(), 2);
+    assert!(validation_result.failures.iter().any(|message| {
+        message.contains(
+            "Sequence function \"GetData\" from sequence call \"package_a.component_a.unit_1\" -> \"package_a.component_a.unit_2\" : \"GetData\" in the sequence diagram not found in the internal API diagram."
+        ) && message.contains(
+            "\"package_a.component_a.unit_1\" -> \"package_a.component_a.unit_2\" : \"GetData\""
+        )
+    }));
+    assert!(validation_result.failures.iter().any(|message| {
+        message.contains(
+            "Methods \"OtherMethod\" declared on internal API interface \"InternalInterface\" in the internal API diagram are not exercised in the sequence diagram."
+        ) && message.contains("\"InternalInterface\"")
+    }));
+}
+
 #[test]
 fn reports_self_call_function_missing_from_available_interfaces() {
     let component_diagrams = component_diagram(vec![unit_without_interfaces("u1")]);
@@ -324,12 +427,40 @@ fn reports_self_call_without_any_available_interfaces() {
 #[test]
 fn reports_method_declared_only_on_caller_side_interfaces() {
     let component_diagrams = component_diagram(vec![
-        unit("u1", &["SharedInterface", "CallerOnlyInterface"], &[]),
-        unit("u2", &[], &["SharedInterface"]),
+        unit_with_fields(
+            "validation.core.example.unit_1",
+            Some("component_alias_1"),
+            Some("Caller Unit"),
+            None,
+            &["SharedInterface", "CallerOnlyInterface"],
+            &[],
+        ),
+        unit_with_fields(
+            "validation.core.example.unit_2",
+            Some("component_alias_2"),
+            Some("Callee Unit"),
+            None,
+            &[],
+            &["SharedInterface"],
+        ),
         interface("SharedInterface"),
         interface("CallerOnlyInterface"),
     ]);
-    let sequence_diagrams = sequence_calls(&[("u1", "u2", "GetData()")]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![
+            sequence_participant_with_fields(
+                "validation.core.example.unit_1",
+                Some("participant_a"),
+                "Displayed Caller",
+            ),
+            sequence_participant_with_fields(
+                "validation.core.example.unit_2",
+                Some("participant_b"),
+                "Displayed Callee",
+            ),
+        ],
+        &[("participant_a", "participant_b", "GetData()")],
+    );
     let internal_api = internal_api_index(vec![
         ("SharedInterface", vec!["OtherMethod"]),
         ("CallerOnlyInterface", vec!["GetData"]),
@@ -341,7 +472,7 @@ fn reports_method_declared_only_on_caller_side_interfaces() {
     assert_eq!(validation_result.failures.len(), 2);
     assert!(validation_result.failures.iter().any(|message| {
         message.contains(
-            "Sequence function \"GetData\" from sequence call \"u1\" -> \"u2\" : \"GetData\" in the sequence diagram not found in the internal API diagram."
+            "Sequence function \"GetData\" from sequence call \"example.unit_1\" -> \"example.unit_2\" : \"GetData\" in the sequence diagram not found in the internal API diagram."
         ) && message.contains("sequence function name was not found in the related interface methods")
     }));
     assert!(validation_result.failures.iter().any(|message| {
@@ -360,12 +491,40 @@ fn reports_method_declared_only_on_caller_side_interfaces() {
 #[test]
 fn reports_method_declared_only_on_callee_side_interfaces() {
     let component_diagrams = component_diagram(vec![
-        unit("u1", &["SharedInterface"], &[]),
-        unit("u2", &[], &["SharedInterface", "CalleeOnlyInterface"]),
+        unit_with_fields(
+            "validation.core.example.unit_1",
+            Some("component_alias_1"),
+            Some("Caller Unit"),
+            None,
+            &["SharedInterface"],
+            &[],
+        ),
+        unit_with_fields(
+            "validation.core.example.unit_2",
+            Some("component_alias_2"),
+            Some("Callee Unit"),
+            None,
+            &[],
+            &["SharedInterface", "CalleeOnlyInterface"],
+        ),
         interface("SharedInterface"),
         interface("CalleeOnlyInterface"),
     ]);
-    let sequence_diagrams = sequence_calls(&[("u1", "u2", "GetData()")]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![
+            sequence_participant_with_fields(
+                "validation.core.example.unit_1",
+                Some("participant_a"),
+                "Displayed Caller",
+            ),
+            sequence_participant_with_fields(
+                "validation.core.example.unit_2",
+                Some("participant_b"),
+                "Displayed Callee",
+            ),
+        ],
+        &[("participant_a", "participant_b", "GetData()")],
+    );
     let internal_api = internal_api_index(vec![
         ("SharedInterface", vec!["OtherMethod"]),
         ("CalleeOnlyInterface", vec!["GetData"]),
@@ -377,7 +536,7 @@ fn reports_method_declared_only_on_callee_side_interfaces() {
     assert_eq!(validation_result.failures.len(), 2);
     assert!(validation_result.failures.iter().any(|message| {
         message.contains(
-            "Sequence function \"GetData\" from sequence call \"u1\" -> \"u2\" : \"GetData\" in the sequence diagram not found in the internal API diagram."
+            "Sequence function \"GetData\" from sequence call \"example.unit_1\" -> \"example.unit_2\" : \"GetData\" in the sequence diagram not found in the internal API diagram."
         ) && message.contains("sequence function name was not found in the related interface methods")
     }));
     assert!(validation_result.failures.iter().any(|message| {
@@ -396,13 +555,41 @@ fn reports_method_declared_only_on_callee_side_interfaces() {
 #[test]
 fn reports_method_declared_on_both_sides_but_not_on_shared_interface() {
     let component_diagrams = component_diagram(vec![
-        unit("u1", &["SharedInterface", "CallerOnlyInterface"], &[]),
-        unit("u2", &[], &["SharedInterface", "CalleeOnlyInterface"]),
+        unit_with_fields(
+            "validation.core.example.unit_1",
+            Some("component_alias_1"),
+            Some("Caller Unit"),
+            None,
+            &["SharedInterface", "CallerOnlyInterface"],
+            &[],
+        ),
+        unit_with_fields(
+            "validation.core.example.unit_2",
+            Some("component_alias_2"),
+            Some("Callee Unit"),
+            None,
+            &[],
+            &["SharedInterface", "CalleeOnlyInterface"],
+        ),
         interface("SharedInterface"),
         interface("CallerOnlyInterface"),
         interface("CalleeOnlyInterface"),
     ]);
-    let sequence_diagrams = sequence_calls(&[("u1", "u2", "GetData()")]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![
+            sequence_participant_with_fields(
+                "validation.core.example.unit_1",
+                Some("participant_a"),
+                "Displayed Caller",
+            ),
+            sequence_participant_with_fields(
+                "validation.core.example.unit_2",
+                Some("participant_b"),
+                "Displayed Callee",
+            ),
+        ],
+        &[("participant_a", "participant_b", "GetData()")],
+    );
     let internal_api = internal_api_index(vec![
         ("SharedInterface", vec!["OtherMethod"]),
         ("CallerOnlyInterface", vec!["GetData"]),
@@ -415,7 +602,7 @@ fn reports_method_declared_on_both_sides_but_not_on_shared_interface() {
     assert_eq!(validation_result.failures.len(), 2);
     assert!(validation_result.failures.iter().any(|message| {
         message.contains(
-            "Sequence function \"GetData\" from sequence call \"u1\" -> \"u2\" : \"GetData\" in the sequence diagram not found in the internal API diagram."
+            "Sequence function \"GetData\" from sequence call \"example.unit_1\" -> \"example.unit_2\" : \"GetData\" in the sequence diagram not found in the internal API diagram."
         ) && message.contains("sequence function name was not found in the related interface methods")
     }));
     assert!(validation_result.failures.iter().any(|message| {
@@ -434,11 +621,39 @@ fn reports_method_declared_on_both_sides_but_not_on_shared_interface() {
 #[test]
 fn reports_role_violation_when_method_exists_only_on_reverse_direction_interface() {
     let component_diagrams = component_diagram(vec![
-        unit("u1", &[], &["InternalInterface"]),
-        unit("u2", &["InternalInterface"], &[]),
+        unit_with_fields(
+            "validation.core.example.unit_1",
+            Some("component_alias_1"),
+            Some("Provider Unit"),
+            None,
+            &[],
+            &["InternalInterface"],
+        ),
+        unit_with_fields(
+            "validation.core.example.unit_2",
+            Some("component_alias_2"),
+            Some("Consumer Unit"),
+            None,
+            &["InternalInterface"],
+            &[],
+        ),
         interface("InternalInterface"),
     ]);
-    let sequence_diagrams = sequence_calls(&[("u1", "u2", "GetData()")]);
+    let sequence_diagrams = sequence_calls_with_custom_participants(
+        vec![
+            sequence_participant_with_fields(
+                "validation.core.example.unit_1",
+                Some("participant_a"),
+                "Displayed Provider",
+            ),
+            sequence_participant_with_fields(
+                "validation.core.example.unit_2",
+                Some("participant_b"),
+                "Displayed Consumer",
+            ),
+        ],
+        &[("participant_a", "participant_b", "GetData()")],
+    );
     let internal_api = internal_api_index(vec![("InternalInterface", vec!["GetData"])]);
 
     let validation_result =
@@ -446,13 +661,14 @@ fn reports_role_violation_when_method_exists_only_on_reverse_direction_interface
 
     assert_eq!(validation_result.failures.len(), 1);
     assert!(validation_result.failures[0].contains(
-        "Sequence call \"u1\" -> \"u2\" : \"GetData\" in the sequence diagram does not match the required/provided interface roles in the component diagram."
+        "Sequence call \"example.unit_1\" -> \"example.unit_2\" : \"GetData\" in the sequence diagram does not match the required/provided interface roles in the component diagram."
     ));
-    assert!(validation_result.failures[0].contains("\"u1\" -> \"u2\" : \"GetData\""));
     assert!(validation_result.failures[0]
-        .contains("\"u1\" should require shared interface(s) \"InternalInterface\""));
+        .contains("\"example.unit_1\" -> \"example.unit_2\" : \"GetData\""));
+    assert!(validation_result.failures[0]
+        .contains("\"example.unit_1\" should require shared interface(s) \"InternalInterface\""));
     assert!(validation_result.failures[0]
-        .contains("\"u2\" should provide shared interface(s) \"InternalInterface\""));
+        .contains("\"example.unit_2\" should provide shared interface(s) \"InternalInterface\""));
     assert!(!validation_result.failures[0].contains("[Method]"));
 }