& @coflags

  Syntax: @coflags <channel>=[!]flag

  Sets object flags for that channel. The flag can be one of: join,
  transmit, or receive.
  
  Transmit: Whether an object can broadcast things over the channel.
  Join: Whether an object can join the channel.
  Receive: Whether a object can receive messages over the channel.
  
  If it is !flag, then that flag is reset. Note that channel flags
  ALWAYS override locks on channel objects.
 
  See also: @coflags, @clist, CHANNEL OBJECT