help/opers/whowas

   1 WHOWAS <nick> [limit] [server|nick]
   2
   3 WHOWAS will show you the last known host and whois
   4 information for the specified nick.  Depending on the
   5 number of times they have connected to the network, there
   6 may be more than one listing for a specific user.
   7
   8 If a limit is specified, WHOWAS will not show more
   9 than that many listings.
  10
  11 The third parameter allows querying another server.
  12
  13 The WHOWAS data will expire after time.