It is possible to flag a post as “rude or abusive” (formerly “offensive”).
For more information on flagging, see "What if I see someone doing something bad?" in the Help Center.
Related: How does the Spam Flag work?
The offensive flag is designed to eliminate truly offensive posts and to penalize the authors:
Even if a post is a bad post for some reason or other, it is probably not offensive. The Offensive flag is meant to be used only in extreme cases, like hate speech, or abuse.
For example, if a user posts obscene images to the site, that should be flagged as offensive. But if someone says something bad about your favorite technology, that probably doesn't apply.
As a rule of thumb, if you can't justify something as being hate speech, or abuse, you shouldn't mark the post as offensive. Instead, you should down-vote the post.
When you decide to flag a post Offensive, you will get a warning dialog. Take this time to decide if the post is really offensive.
There is often no need, as offensive flags expire after 48 hours if the thresholds aren't reached.
Rolling back a post to a previous state will revert to the number of offensive flags from that particular revision. This allows the OP (or someone else with edit rights) to rollback a post that someone else made offensive in a later revision. However as a general user, once you mark a post as offensive, you cannot take it back.
If I understand correctly, if I mark an answer offensive and the person whose answer it is doesn't agree, that user (or anyone else with enough rep) can remove that offensive tag, but I can't. Does that make sense? If I downvote a question, nobody can remove that downvote except me, and even I can't after a long enough period of time. So why should someone else be able to remove my offensive tag?
Edited to add a clarification. After a brief email conversation with (someone?) at [email protected], I can now say that my concern is unfounded. You can roll back revisions of questions or answers, but adding an offensive flag is not a revision. So if someone posts a question that is offensive and I mark it as such, the poster cannot roll back the question to get rid of my offensive flag, since the question is still at revision 1 so there's nothing to roll back to. If someone posts a valid question and someone else modifies it to be offensive, then the original poster can roll it back to his revision, thereby removing both the offensive content and any offensive tags.
There is still the potential for abuse -- someone could post an offensive question and then quickly post a small revision to it. If he did that before the original revision was marked as offensive, then he'd always be able to roll back to revision 1, thereby removing any offensive tags. But I think the likelihood of this is low. If it gets to be a problem, Jeff and the boys can revisit it.
You are facing a difficult problem here: your post about "what is offensive" makes it clear the matter is subjective and that one must avoid applying the tag lightly because the consequences are fairly severe. That being the case, it is guaranteed that there will be times when the flag is inappropriately used. Yet you lack a process for handling those cases, and this is going to hurt the community.
I had a question marked offensive when there was nothing offensive about it. By the very criteria I just read above, it should not have happened. If I am going to care about reputation and work on building it, then I should have a process whereby I can state the case for my defense when 100 rep is taken from me.
What process is there for that to happen?
BTW, here's the question that was deemed offensive (as best I can remember ... it was blown away within 2 minutes).
(Note: Granted, it is not the most value-adding question in the world. I was feeling goofy, and the metaphor of a "virtual beggar" crossed my mind. Plus, I think I partly misunderstood the meaning of the "community wiki" flag. So delete it ... but how does it justify the "offensive" flag?)
Subject: Will you please vote me up? I have a disease. (Imagine me as a beggar on the sidewalk).
Post Text Ha ha, just kidding (which is why I marked it "community wiki").
And let me emphasize: it was marked as "community wiki" from the outset. There is no way I could have garnered any rep from it.