Time was, extra language codes for Wikidata labels were added by adding them to the `wmgExtraLanguageNames` in the `wmf-config/InitialiseSettings.php` (for the wikidata dblist and later also commonswiki). This was bad for several reasons, and so we eventually moved that configuration to Wikibase ({T260118}). However, soon afterwards we added the `wmgExtraLanguageNames` back to the production config ({T264295}). We would like to remove it again to avoid confusion and issues – for instance, {T272242} happened because the language code `'dag'` was added to the Wikibase list but not the `wmgExtraLanguageNames`.
Removing the production `wmgExtraLanguageNames` is blocked on at least two tasks:
* {T124758}. This is the original reason we reinstated `wmgExtraLanguageNames`: without it, those additional languages are harder to use.
* {T273625}. Language codes like `kea`, `nod` and `ota` are currently only available for Lexemes on Wikidata because they are in the `wmgExtraLanguageNames` – they’re also in the Wikibase language codes, but WikibaseLexeme currently doesn’t use those. If we remove `wmgExtraLanguageNames` before T273625 is done, then those language codes will become unavailable for Lexemes on Wikidata.