Some games let you display a clan tag before your name, for example [Irkn]IrkenInvader.
Mine is [MIZ], I randomly ran into someone with [RKO], the kid sent me friend request and a message saying "The Miz is not awesome, okay, kay....kay Randy Orton is, got it."
How weird is that?
Even weirder I just switched my clan tag from [RKO] last night. I've never had someone recognize what it meant.