@SYNTAX:whowas@

This command is similar to WHOIS, except it returns information 
about nicknames that were recently in use. Like WHOIS, it shows 
the nickname, address, real name, and server. It may also return 
multiple entries if the nickname has been used recently by several 
people. These multiples may be limited by specifying a count to show. 

WHOWAS will work regardless of whether the queried nick is in use. 
If no arguments are given, the client's current nickname is used. 

Example: To show the last 5 users of the nickname JoeBob: 

/whowas joebob 5 


See also: WHOIS