In one embodiment, {HEAD ~ messages} may be sent only to the one or more endpoints bound to {TAIL ~ the pipe} 
In one embodiment , { HEAD ~ messages } may be sent only to the one or more endpoints bound to { TAIL ~ the pipe }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL