These mechanisms may include {HEAD ~ a set} of one or more pattern matching masks and {TAIL ~ a count indication} into the packet as to where pattern matching will begin 
These mechanisms may include { HEAD ~ a set } of one or more pattern matching masks and { TAIL ~ a count indication } into the packet as to where pattern matching will begin
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH