First export from translatewiki.net with https://gerrit.wikimedia.org/r/c/mediawiki/core/+/1161336
- Verify autonym correctness in language-data
- Add to Wikifunctions's language list in function-schemata https://gitlab.wikimedia.org/repos/abstract-wiki/wikifunctions/function-schemata/-/merge_requests/236
- Add to includes/languages/data/Names.php (patch)
- Add to RELEASE-NOTES (patch)
- Set fallback if needed (ru)
- Add namespace translations (requested)
- Check that namespace translations don't conflict with language codes
- Add $linkTrail
- Remove from translatewiki after deploying the core change (patch)
- mw-config/LanguageSettings.php
- mw-config/FallbackSettings.php
- Test language search in UniversalLanguageSelector and fix the search index (if needed)