Each of {HEAD ~ the side surfaces} has {TAIL ~ an inset} spanning from the block top surface to the block bottom surface 
Each of { HEAD ~ the side surfaces } has { TAIL ~ an inset } spanning from the block top surface to the block bottom surface
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH