Great point about Anchoring; mine get killed all of the time. But it was implied that there's a way for someone to tell that a mob is your anchor. I've never noticed, and this is something I'd love to know. How do you tell when a mob is being used as an anchor? I usually use the first boss I come upon, but there are frequently multiple bosses in large fights, so I can't just say "I'm tagging the boss".
(Here's hoping it's not something completely obvious that I missed.)