diff --git a/.github/workflows/managed-files-guard.yml b/.github/workflows/managed-files-guard.yml
index 3fe74e4..5973dc1 100644
--- a/.github/workflows/managed-files-guard.yml
+++ b/.github/workflows/managed-files-guard.yml
@@ -14,7 +14,7 @@ name: managed-files-guard
 # it is given and fails the pull request when the diff hand-edits one of them
 # (ADR-0007: a managed file is byte-exact with its standards source; the fix
 # path is a standards change, never a downstream edit). Pull requests opened
-# by the sync itself — labelled `standards-sync`, or authored by
+# by the sync itself — labeled `standards-sync`, or authored by
 # `melodic-standards-sync[bot]` — are exempt inside the action.
 #
 # ADVISORY during soak (standards#496): this check is NOT aggregated into
diff --git a/_typos.toml b/_typos.toml
index 531cf46..34e03a4 100644
--- a/_typos.toml
+++ b/_typos.toml
@@ -7,6 +7,10 @@
 # stay minimal.
 
 [default]
+# American English is the house language: non-American variants are corrections,
+# not accepted alternates.
+locale = "en-us"
+
 extend-ignore-re = [
   # Inline ignore directives. typos has no built-in pragma, so this config
   # blesses a convention: silence a single line, the following line, or a
@@ -49,6 +53,10 @@ DUM = "DUM"
 FO = "FO"
 # Features on Demand (Windows optional-feature packaging) — provisioning.
 FoD = "FoD"
+# The MITRE Corporation (MITRE ATT&CK, the CVE program) — review conventions.
+# The en-us locale corrects the woodworking joint's British spelling to "miter";
+# case-sensitive and whole-token, so that correction still applies to prose.
+MITRE = "MITRE"
 # CC BY-ND license abbreviation (NoDerivatives) — claude-code-proxy.
 # Case-sensitive and whole-token, so lowercase "nd" is unaffected.
 ND = "ND"