@FAIL (ME|HERE|thing|#nnn|[+]group) [=(message)]
Sets the fail message for (object). This message is displayed
to a player when that player fails to use (object) or to be added
to a group. Failure messages on groups are also displayed when the
player loses their membership in that group. Without an argument,
@fail clears the message.
An @fail message on yourself will tell a player who is paging you
why you're not accepting pages, should you care to tell them.