I rarely mark unless there is "special" reason for it. Sometimes there are mob stunning/paralyzing or doing annoying AoE so I mark them, but I don't expect people to stop doing AoE because there is marked one, just be sure that if you do something to single target hit that one.

Quote Originally Posted by Fyce View Post
It leads to situations where all 3 enemies of a pull (or more) will remain alive until they're all close to death.
Well basically with AoE dps that is the fastest way to do it. Healers dps is too low to make any difference againts BLM hitting 3 targets, but yeah pretty much all tanks know what you are talking about