Seems that the new moderators are in action and I got really confused about my two declined comment flag. The first is a comment in this answer, where the answer-er asks why someone downvoted their post. But their post is just NOT downvoted so I don't see any point of keeping that comment. (Maybe next time I should use a custom flag? I thought it is obvious though...)

And for the second one, I flagged both two comments below this answer, and one flag got declined and the other marked helpful. This time I really don't know how to interpret this.

Hello. My understanding is that it's poor behaviour for question-askers to change their question after an answer to their original one has been provided. This happened to one of the questions I posted an answer in, and I pointed this out to the OP. Should I leave it at that, or should I roll back to the original question and insist that the OP post a new one?

@TheoreticalEconomist It would be quite helpful if you'd also include a "go-to" link to the question you speak of.

@amWhy I considered adding a link, but I didn't want to draw unnecessary attention to the offending post. I was hoping there was a general guideline to deal with cases like the one I described without getting too caught up in the details of specific posts.

But, since I've been asked, here it is: math.stackexchange.com/q/2880527/388944

@TheoreticalEconomist Ahh, I understand now.

@amWhy awesome. Any thoughts?

I've cast some votes there. Also, given that the question had been asked on August 12, 5 days ago, and was only edited four hours ago, I think it is certainly justified to roll-back the edit.

Ok. So I'll consider how long between the edit and the original post in case this happens again in the future. Thanks for the input, and rolling it back!

I just rolled the edit back to Joriki's edit including one additional tag, prior to the edit. You might want to edit your comment (below the post) to keep it up to date.

The comment is too old to edit. I'll leave it there for the OP to see.

@TheoreticalEconomist Typically, changing or correcting a post might be frowned upon, but, say User x asked question y. Within 2 minutes, user z answers question y, but user x was already in the process of editing out a confusion pointed out in a comment. I think an early edit to a problem is perfectly understandable, and that anyone answering two minutes after a question is submitted ought to be prepared for some fine-tuning of the question, and perhaps, fine tuning of their answer.

It's the middle ground that gets messier, but in your case, changing a question late in the game is never appropriate, given it already had at least two answers.

@amWhy Well, personally I'd be a little more forgiving about fine-tuning in the question that would require some tweaking with the answers, which sounds a lot like the first case you describe (sans the considerations of timing). I was more curious about the latter case where the question is completely different, like in this example: originally, the question was about notation but evolved into a question about a proof.

But the timing is certainly important; I hadn't thought of that. Thanks again!

@TheoreticalEconomist When an asker posts what is clearly a different question, asked after they got an answer to their first question, that's wrong to pull off. In that case, you should probably flag the question "for moderator attention", describe the issue, and it will likely get handled by a mod.

@JohnMa I messed up. Sorry, I accidentally hit "dismiss" instead of "delete", but then I quickly went to delete the comment.

@JohnMa I declined those because while I agree that thank you/you're welcome are not very useful, there's some merit for keeping them recently after the exchange.

So I agree that the comments can be deleted. But a bit later.

I mean, my point is that we could also use a little more civility. And having thank you comments doesn't really cause any harm. If it were up to me, I'd keep them forever when they don't cause an issue (i.e., if there are no other comments on the answer), but I also understand why some people feel otherwise and that it's better to delete them.

But at least for those recent ones I'm in favor of giving more leeway. If those are a few weeks, or months, or even years old, that's a different story altogether.

@AsafKaragila Thanks for explaining your stance on those comments. And I can understand that some might think it is too soon to delete those two. My confusion is instead the combination: I am expecting either two "helpful" or two "declined". But one "helpful" and one "declined" seem to be a mixed signal which I don't know how to interpret.

@JohnMa hi

Can I ask question in chat?

@YODA Math questions?

It can happen that one asks a question that has a somewhat trivial answer but there is a deeper "intended" question. So one can ask whether every X is a Y, get an answer by Alice and then write something like: Is every X a Y. By the answer of Alice below, we know this does not hold if we don't assume Z. So is every X a Y under Z?

I flagged a thing, but I cannot unflag the thing. If a mod would be so kind as to decline the flag here, I would feel better about my life choices.

That being said, that entire question has become toxic. Perhaps a moderator would like to drop in share some wisdom?

@TheoreticalEconomist Right, changing a question after getting an answer is a no-no, with some exceptions for adding constraints that were forgotten in the original. That can be legitimate. When somebody substantially changes their question after getting an answer, rolling back is appropriate. If one can't roll back oneself, or feels uncomfortable doing so, flagging is appropriate (but we have enough flags to not get bored, so if it can be resolved without moderator intervention, all the better).

If the asker insists, and changes the question again, that is a point to flag even if one can roll back and is comfortable doing so.

@XanderHenderson Sorry, couldn't. That comment was too toxic to not delete.

Ah, well, then.

That is fine, too.

That whole thread sucks. :(

Yes, the most fitting description of it is "Ugh".

I hope, @DanielFischer, that my explanation to Theoretical Economist was not too far off the mark. Of course, I should have encouraged them, in the future, to roll-back the inappropriate significant edit by an asker, which is what I did in this case, and if that fails, as you described, to flag. Sorry if I added any potential burden to the mods' work.

@amWhy You hope not in vain, your explanation is good. And thanks for the roll-back. (I had for some reason not scrolled down enough and read everything.)

@XanderHenderson Looking at another timeline, I see that a colleague had already declined what I now think is the flag you were referring to here, and when I went to the page, I only saw your next flag on that page. Now everything makes sense again. I couldn't really understand why you'd want to retract that later flag.

Yeah, the latter flag needed to be dealt with.

The first one was a result of my profound confusion.

In any event, thanks!