This event is activated whenever someone sends a client-to-client protocol (CTCP) request. Certain CTCP types have predefined actions that you can't override with the ^, but you can use the - to create your own ctcp protocols. The parameters are:
        $0      nick of person who send CTCP
        $1      who the ctcp was to (either your nick or a channel)
        $2      The CTCP command word
        $3-     Any additional arguments
  For example, if you want to set up a new ctcp function called 
  CHEESE, you  would do:
    ON -CTCP "* * CHEESE" CTCP $0 $2 Say Cheese!
  Using the /ctcp in an ON CTCP automatically sends the proper 
  reply format.  If someone sends you a:
    CTCP <yournick> CHEESE
  you will see:
    *** CTCP CHEESE from <theirnick>:
  and they will see:
    *** CTCP REPLY CHEESE from <yournick>: Say Cheese!
  
See Also:
  ctcp
  on/ctcp_reply