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