ircII help: msg

Usage: MSG <nicknames>|<channel>|%<pid>|=<nick>|@<user>|<n>|<command> <text>
  Sends a private message to the nicknames or list of nicknames
  specified.  A list of nicknames should by separated by commas
  (no spaces).  Three special case nicknames are defined.  If the
  nickname is "," (a comma), the message is sent to the last
  person who sent you a MSG.  If the nickname is "."  (a
  period), the message is sent to the last person to whom you
  sent a message.  If the nickname is "*" the message is send to
  the current channel.

  The second form allows you to specify a channel name to which
  to send the message.  The message will go to everyone on that
  channel.

  The third form specifies an EXEC process id to send output to.

  The fourth form allows you to specify a DCC CHAT connection over
  which to send the message. The nick specifies the nickname under
  which the connection was established.

  The fifth form allows you to specify a DCC TALK connection over
  which to send the message. The user specifies the user part of
  the user@host used to establish the DCC TALK connection.

  The sixth form lets you specify a process number to which the
  message will go, where n is the process number.  This works
  just like the EXEC -IN command.  For example:
    MSG %1 Homina homina homina
  will send the text to process 1.  Process 1 must be running
  already using a previous call to EXEC.
    
  The last form allows messages of the type MSG COMMAND <message>
  which allows you to send a message to some command.  Try MSG /ECHO blue
  This is meant to be used with QUERY primarily.

*  There is also a use of wildcards for operators.
*    MSG $*.edu
*  will address all users having .edu in their serverinfo.
*    MSG #*.edu
*  will address all users having .edu at the end of their host name.
 
See Also:
  SET BEEP_ON_MSG
  EXEC