{TAIL ~ The block back legs} may extend in {HEAD ~ a plane} parallel to the block front surface or extend forwardly toward the blocks front surface 
{ TAIL ~ The block back legs } may extend in { HEAD ~ a plane } parallel to the block front surface or extend forwardly toward the blocks front surface
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH