Language configuration and translation assignment
Control the actual output language code of the site configuration. Locale designation and hreflang value perform different technical tasks.
Compare site languages, basic URLs, and the translations that actually exist. A detail extension must assign the same data sets and accessible paths as the output language references. Language fallback and real translation are not always the same content.
Where to check the setting in TYPO3
Control the languages of the site configuration and the translation relationship of the page or dataset. hreflang must match accessible language versions. A fallback output with unchanged content is not automatically an independent translation.
Example of this specific finding
Illustrative control case: One site uses de-UK for German-language content in the United Kingdom. Region and language code were not assembled according to the supported codes.
follow-up audit in TYPO3
Open the other versions from each language version and check their canonical and reference back. Do not replace an empty or unavailable translation with a foreign homepage.
Determine the actually meant language and optional region. Use only supported combinations, such as de or de-GB; check URLs and backlinks thereafter.
Derogations and scope
A region alone is not a language. x-default has its own task as an assignment for non-specifically covered users and is not an ordinary language code.
Reference: TYPO3 13.4 with EXT:seo. For other major versions and own extensions, responsibilities may differ; check the actually installed output.
Classify the general error
Definition, system-independent causes and further correction examples: Check language code and optional region separately