Translatewiki
This extension is translated at Translatewiki.
Some messages are special markers, and should not be translated. It may still be necessary to adapt them somehow, and in those cases special care must be taken to not disturb normal parsing.
The descriptions (the qqq-messages) marked as {{Optional}} goes in the group mwgithub-pickle in the file groups/MediaWiki/mwgithub.yaml at the repo for Translatewiki. The public configuration repository can be found at Phabricator.
A common EPIC used for bug tracking is found at T169455 — Maintenance of optional and ignored messages.
To extract the optional messages use
fgrep '{{Optional}}' i18n/qqq.json | grep -o ".*:" | grep -o "[-a-z]*"
To extract the ignored messages use
fgrep '{{Notranslate}}' i18n/qqq.json | grep -o ".*:" | grep -o "[-a-z]*"