Flagging Rule-breaking posts is great, It helps the mods keep this place clean of spam and off-topic discussion.
However, sometimes, you might not want to wait for a moderator to log on and handle your flag, and sometimes, the question might just be a little bit low on the quality, but not so bad that a moderator will actually delete it when you flag it.
So, I'd like to share with you this little-known feature that you can use, to sort answers you disapprove of, such as incorrect or incomplete answers to the bottom of the default sorting order.
In order to use this feature, you have to click a button that appears to the left of the post. The button looks like an arrow pointing down.
We call this feature a downvote.
I get the sense that multiple users are unaware of this feature, because although they seem to know of the ability to flag a post as "not an answer" or "very low quality", posts with those flags will too often have no downvotes on them at all.
So, please downvote posts that you have a problem with. It's actually a very effective way to keep people from writing a post they're not confident in. You can even down-vote a post that you've flagged, and if that post ends up getting deleted, you get your 1 reputation back.