This command sets the message that is shown to anyone who kills <object>.
This attribute is only meaningful for players and things, and will never be automatically triggered on other object types.
Function references and %-substitutions are allowed in kill messages, and are evaluated when someone kills the object. In function references, 'me' refers to the object that was killed, while %-substitutions that refer to the enactor (such as %n, %#, %p, etc) refer to the player doing the killing.
Example: @kill guard = The guard says "I'll get.. you... for... this... %n" as he falls down and dies.