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

======Description:======
This hook is triggered whenever the client sends a [[MSG]] to another user.
It is only triggered when sending messages to individual clients, not
to channels.

======Parameters:======
|$0 |nickname message is sent to|
|$1- |text of message sent|