{HEAD ~ means} for indicating the halting of the actuation of the plurality of {TAIL ~ assignable user actuated switches} or keys; and 
{ HEAD ~ means } for indicating the halting of the actuation of the plurality of { TAIL ~ assignable user actuated switches } or keys ; and
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH