Client To Client Protocol(CTCP) A type of {protocol} created to allow structured data such as {font} information to be exchanged between users on {IRC}. It is also used to send a query to a user. The available CTCP commands include VERSION, FINGER, DCC CHAT, DCC SEND, TIME, PING, ECHO, CLIENTINFO. Some commands are not available on some IRC {client} software. (1995-04-12)