diff --git a/docs/admin/configuration/default-language.md b/docs/admin/configuration/default-language.md
index dceb9b41..ac4cc255 100644
--- a/docs/admin/configuration/default-language.md
+++ b/docs/admin/configuration/default-language.md
@@ -8,9 +8,11 @@ draft: false
 
 # Set the default language
 
-By default, OpenCloud uses English (en) as its interface language, unless a different language is explicitly configured.
-OpenCloud relies on ISO 639-1 language codes for language selection.
-You can find the complete list of supported languages here: [Supported languages](../resources/faq#miscellaneous)
+The system default language applies when a user has not selected an individual language. It is used by the WebUI and services such as notifications and userlog, and can determine the language of notification and invitation emails. If no system default is configured, OpenCloud uses English (`en`).
+
+Users can select their preferred language in the WebUI under Account > Language. This individual preference takes precedence over the system default.
+
+OpenCloud uses ISO 639-1 language codes. See [Supported languages](../resources/faq#miscellaneous) for the available languages. If a requested locale includes a territory and no matching translation is available, OpenCloud first tries the base language. If a translation for a user's preferred language is unavailable, OpenCloud falls back to the configured system default and then to English. Without a configured system default, it falls back directly to English. For details, see the [settings service translation rules](../../dev/server/services/settings/information#translation-rules).
 
 ## Edit the `.env` File
 
@@ -20,15 +22,14 @@ Open the environment configuration file located in your `opencloud-compose` dire
 nano opencloud-compose/.env
 ```
 
-Configure the default language using the following environment variable:
+In `opencloud-compose`, `DEFAULT_LANGUAGE` maps to `OC_DEFAULT_LANGUAGE` inside the OpenCloud container. Set the system default to German, for example:
 
 ```env
-# The default language used by services and the WebUI.
-# Uses ISO 639-1 language codes (e.g. "en", "de", "fr").
-# Defaults to English if not set.
-DEFAULT_LANGUAGE="language code"
+DEFAULT_LANGUAGE=de
 ```
 
+When configuring OpenCloud directly without `opencloud-compose`, set `OC_DEFAULT_LANGUAGE=de` instead.
+
 ## Restart Docker Services
 
 After saving the file, shut down and restart the Docker containers to apply the changes:
@@ -40,4 +41,4 @@ docker compose up -d
 
 ## Result
 
-OpenCloud is now fully displayed in the language configured in the .env file.
+The configured language is now the system default. It applies to users without an individual language preference and to services that use the default language. A user's language selected under Account > Language takes precedence. If translations are unavailable or incomplete, OpenCloud applies the fallback behavior described above, so some text can appear in English.