[takoi]

keep in mind that certain strings may not be used by core or confluence, but they might be widely used by other skins.
removing strings from the language file is not so easy as it seems ;-)

Good reason to remove them then. Random strings with no context are basically untranslatable.

I actually made a script for checking for unused string like this some years ago; if only I could find it. It should work well enough to get draft. The hard ones are the string ids with 4 digit and less, which will usually just give too many false positives. And iirc there are some funky arithmetic going on for the weather strings to be wary of.