Usage: ON [#|+|-|^|&|@]RAW_SEND [-|^]<parameters> [action]
  This is activated whenever a message is sent to a.

IMPORTANT NOTE: ON RAW_SEND can and will seriously impede the operation
  of the client if not used correctly.  If you use ON ^RAW_SEND to
  suppress message sending then the client will not send it to the
  server. Be careful.