& DARK
 
  Flag: DARK(D)
 
  If a room is DARK, then no items are shown when a person 
  'looks' there. If a thing is DARK, then "look" does not list that 
  object in the room's Contents:, and if an exit is DARK, it doesn't 
  show up in the Obvious Exits: list.  Puppets and objects that can 
  listen cannot be DARK.