When someone uses Agony/Malefic Wreath on me in PvP, I know they're new here...

When someone spams Rushed Ceremony every time they're at 20% health, I know they're going to take an extra 5-10 minutes to kill

When someone runs a heavy-armoured, S&B, vamp DK, I suddenly turn into the "better man" and walk away from the fight #makelovenotwar (despite the fact that it is PvP and we're here for fighting)

Make some of your owns - I mostly PvP so that's what mine are orientated around, but I think they could be pretty broad.