The ribbon has a small thickness to prevent obstruction of {HEAD ~ the elements} bordering {TAIL ~ the top flange} and the upper surface of the top flange 
bordering
The ribbon has a small thickness to prevent obstruction of { HEAD ~ the elements } bordering { TAIL ~ the top flange } and the upper surface of the top flange
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH