We use flags here in a way which is good given the nature of our site. However, these are different than what other less "subjective" sites use.
I would love to see a flag for the following:
- Does not add anything unique. We get lots of answers which are effectively smaller versions of other answers which often get hit with "not an answer" or "very low quality." I think these answers are not good for the site and I will continue downvoting them (see here)
- No justification given. Something to cover the many drive by "here's my thoughts with no explanation" types of answers which don't even come close to satisfying the "back it up" idea. I also downvote many of these, especially short 'comment' answers.