As a moderator on a couple comment-heavy sites, I see a lot of "no longer needed" comment flags. But that doesn't tell me why it's no longer needed, so to evaluate it I usually have to read through a bunch of other comments or review edits to try to figure out what the flagger had in mind. But the flagger already knows why it's obsolete -- if only he could tell me, without ignoring the built-in flag reason and resorting to an "other" flag.
Could we add one more mouse click to "no longer needed" flags? Maybe something like this, after a user flags as obsolete:
The first two options cover the vast majority of such flags I see, though other sites might be different. I don't know if the third happens enough to be worth the menu space. I sometimes see such flags on comments that are just plain old -- "@user ^^^" to get someone's attention, comments like "I'll edit in sources tomorrow" (and it didn't happen), etc. That's the sort I had in mind with this option.
I don't know if an "other" option should be offered. And this menu doesn't allow for a "naked" flag (no further explanation); I don't know if that's good or bad. So I'm not proposing this exact implementation, but am instead asking if some further explanation of obsolescence could be supported in the flag UI.
After posting this I was reminded that I'd previously asked another question arising from the same problem. In that feature request I asked that flaggers be identified, and the response was that that wouldn't help all that much. This is asking about allowing the flagger to directly communicate the reason rather than leaving it to mods to figure out. Can we do something to add information to the obsolete flag?