& @lock

  Syntax: @lock[/<whichlock>] <object>=<key>
           @lock <object>/<attrib>
 
  The first form locks <object> to a specific key(s).  Type 'help 
  @lock keys' for a list of the keys you may use.
 
  <whichlock> indicates which lock you want to set on the object.  
  If you don't specify one, you set the Default lock. Type 'help 
  @lock locks' for a list of the locks you may set and what they are 
  used for.
 
  The second form locks the indicated attribute of the named object, 
  so that when the object is @chowned, the attribute will remain 
  owned by you. It may also be used when you own an attribute on an 
  object that you do not own, in this case it prevents the object's 
  owner from @chowning the attribute to himself, and prevents anyone 
  from modifying or removing the attribute.
 
  See also: @chown, @unlock, @lock locks, @lock keys, @lock attribute, 
  @lock evaluation, @lock indirect, @lock normal, @lock is, 
  @lock carry, @lock ownership, @lock compound