Literature
All My OCs and Even There Parents~
*PC = Player Character, or a character that is one you want to consider your own and whatnot.
*OPC = Other Player Character, or a character that is real but is controlled by another's will. [i.e. John really loved his OC, StupidFace. He would play the PC all the time. However, he liked Kate's OC, Pedobear, much more, but seeing as though it was an OPC, he couldn't RP Pedobear without Kate's permission. Unless established beforehand.]
*NPC = Non Player Character, or a Not Playable Character. It's still a character but you could care less to whether or not someone calls it your own or not. A NPC is, also, usually a character that is us