Also, {HEAD ~ the client B} 300 and the client C 400 also leave {TAIL ~ a trace} 
leave
Also , { HEAD ~ the client B } 300 and the client C 400 also leave { TAIL ~ a trace }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL