This is an rcirc extension. It replaces all the nicks with random names pulled from a list. It adds nick completion as well, so other channel members should not be able tell you are doing it.
Maybe this will provide the illusion of a 50:50 gender presence online. It’s probably also confusing as hell.
To alleviate the confusion, there’s the realname command:
/realname NAMEwill show you the appropriate nick to random name mapping.
/realnameby itself will show you all the nick to random name mappings.