Synopsis:
   on [<modes>]notify_signon [<serial#>] [-|^]<match> { <action> }

Description:
   This hook is triggered whenever the client detects that a nickname on its
   internal NOTIFY list has signed on to irc.

Parameters:
   $0    nickname that signon was detected for
   $1    user@host of person signing on (if set(4) notify_userhost_automatic
         is ON)

See Also:
   notify(1); set(4) notify_userhost_automatic; on(5) notify_signoff