First export from translatewiki.net with https://gerrit.wikimedia.org/r/c/mediawiki/core/+/666794.
- Understand whether it should be Latin script, Mongolian script, or both. -> Both
- Understand whether an autonym in Latin should be added, and what should it be. -> Yes
- Configure both in translatewiki
- Move Mongolian-script translations in translatewiki to mnc-mong
- Move Latin-script translations in translatewiki to mnc-latn <-- We are here
- Make necessary changes in language-data, if needed.
- Add to Names.php (T338116)
- Remove from translatewiki.