WHO

Usage: /WHO [<name> [<o>]]

Returns a generated list of all users matching the criteria passed to
the command, i/e. everyone at a particular site, or on a particular
server.  If the optional <o> argument is specified, /WHO will only
return information on users that are channel operators.

EXAMPLES:

/WHO *.cmu.edu
     Will list all users at the cmu.edu domain.

/WHO irc.pitt.edu o
     will list all operators on irc.pitt.edu server