Useful Terms ((Work in Progress, sorry folks))

PK - player killer - Someone that hunts/kills other characters/players in The World.
PKK - player killer killer - Someone that hunts/kills the PKs (player killers) within the World.
PC - player character - a character that is played by a person, rather than being an NPC
NPC - non-player character or no paritcular character - a character that is not controlled by a person; just another portion of the game.
Epitaph User - Anybody who has an avatar of one of the eight phases
Class - the rank or job of a character. Ex., Steam Gunner.