I'm pretty new to Puzzling, but I've looked over a few meta posts about "difficulty". We don't have tags for difficulty ratings, and we don't seem to need a star/rating system IMO.
Yet people label their puzzles regardless:
- Mysterious Murder Mystery 3 (Very Hard)
- The SErial Killer's killer [Difficult]
- The Animal Party [Security to the Party 26] - an easy one
- Spatial IQ test puzzles - Very hard
I think this has all the problems Doorknob mentioned in his answer, with the addition of cluttering up the titles on the front page. Square brackets are particularly bad to me, since that's how [closed], [on hold], and [duplicate] show up. Having excessive brackets makes it more difficult to skim/scan.
I'd like to edit them all out (and continue to do this as I see them), but would like to hear the community's opinion first (since like I said, new here).
To be clear, I don't care if the poster says whether they believe it's hard or not if it's worked into the body. However, the title shouldn't have this meta information.