From this session S1, the client 20 can perform {HEAD ~ 610 changes} to the feature instances F1 and {TAIL ~ F2} 
to
From this session S1 , the client 20 can perform { HEAD ~ 610 changes } to the feature instances F1 and { TAIL ~ F2 }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL