There's a strange behavior that's been around probably since release that I've never seen a use for. In fact, it actually causes me problems in battle, and it's bothered me enough now that I had to post this. When a mage casts a spell on you (Protect, Shell, Cure, anything directly targeting you) if you are not targeting anything at that time you will auto target the caster.
Seems pretty petty right? Well, not when you're in the middle of battle and switching between a mob after you've defeated one. You expect to be able to just auto target the next one (or use a key combo macro like I do with my gamepad for /targetnpc) but then you find your target doesn't change. Why? Because you're now stuck on the mage who cast Shock Spikes on you, and you have to hit the cancel button once or twice to get off that target and onto the mob.
I don't see any useful need for this feature. I don't need to know who cast a spell on me in my party, that's what the battle log is for. Please give us a way to disable this, or just get rid of it outright!