Somewhere in options is a checkbox that will prefix all messages with what "type" they are.
e.g.
[Your Hits]You slash A Fluffy Bunny for 2058 points of damage!
Unfortunately I'm not home to find exactly where that option is. If nobody else has responded by the time I get home I'll look it up and let you know. That option is invaluable when shuffling these odd messages to their own windows. I almost want to say the experience message is part of [Loot Messages] or something, but again, just going off memory here.