Strings get changed over time, but sometimes they only be removed from the actual source file (cxx) while they still exist in hrc and src (and in the Pootle platform).
(And many in that file)
Isn't there a way (e.x.: a script) to ensure that all the strings that are in hrc and src are actually used by LO?
Might be a good easy hack.
This is what  does, but probably we should run it from time to time.
(In reply to Gabor Kelemen from comment #2)
> This is what  does, but probably we should run it from time to time.
Yes. I discussed with devs and there does not seem to be a need to change this to an easy hack. Thanks.
Caolán McNamara committed a patch related to this issue.
It has been pushed to "master":
Related: tdf#100226 unused hrc defines are the same as hxx defines now
It will be available in 6.1.0.
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.