Ask HN: What is the correct use of the flag button?

The right way to think of the comment flag button is as a signal to the moderators. "This comment is so bad, it demands some of the scarce time and attention of the moderators".

That's not all the flag button does, but if you think about it that way, you'll end up flagging the right comments.

From https://news.ycombinator.com/newsguidelines.html:

Please don't submit comments complaining that a submission is inappropriate for the site. If you think a story is spam or off-topic, flag it by clicking on its "flag" link. (Not all users will see this; there is a karma threshold.) If you think a comment is egregious, click on its timestamp to go to its page, then click "flag" at the top.

If you flag something, please don't also comment that you did.

I do think more examples of when flagging isn't appropriate would actually be helpful. And finding the instructions above isn't very easy, I wish they appeared elsewhere in HN's UI.

I flag stories that produce mean stupid or unproductive discussions or that I believe will based on experience. On the other hand, a comment has to be vile enough to justify calling for moderator attention before I flag it.