This is performed by identifying conditions necessary to change {HEAD ~ a coded syntax element} without disrupting {TAIL ~ the interpretation} of subsequent coded elements 
This is performed by identifying conditions necessary to change { HEAD ~ a coded syntax element } without disrupting { TAIL ~ the interpretation } of subsequent coded elements
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH