Several i18n messages in TimedMediaHandler appear to be unused. I discovered it as I was doing some informal auditing of Extensions used by Wikimedia in translatewiki and noticed that some TimedMediaHandler messages were documented as "May unused" (sic) by @Umherirrender in qqq.
I ran git grep and here's what I found:
These messages don't appear anywhere outside json files:
These are mentioned in the code, but I couldn't find where exactly. If they can actually be seen by users, it would be great to document them properly in qqq. If they are not actually seen, the messages and the corresponding code must be removed:
Similar task: T224429: Hunt and remove unused i18n messages in mediawiki core