@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.

Thanks to Eagle's brainstorm and Isaac's coding, %substitutions now work
in @succs and @fails instead of only in @osuccs and @ofails. These work on
exits, actions, copy-objects and groups. This will NOT work when adding a
group to a room.

See also: @ofail, substitutions