selecting {HEAD ~ one or more transport packets} of {TAIL ~ said one or more transport streams} for output in a remultiplexed transport stream, 
of
selecting { HEAD ~ one or more transport packets } of { TAIL ~ said one or more transport streams } for output in a remultiplexed transport stream ,
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH