The middle section 48 includes {HEAD ~ a series} of notches 56 and {TAIL ~ raised portions} 58 of a type well known in the art 
The middle section 48 includes { HEAD ~ a series } of notches 56 and { TAIL ~ raised portions } 58 of a type well known in the art
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH