CoX

CoX

Common abbreviation of "City of X". A shorthand way of referring to both City of Heroes and City of Villains at the same time.

The "X" comes from algebra where letters (commonly X) replace unknown numbers. Prior to the general adoption of CoX, players often typed "CoH/V", short for "City of Heroes/Villains". You will also see "Co*", which uses the asterix (*) as a wildcard.