{HEAD ~ The circuit board} has {TAIL ~ a groove} in a section of a surface of the circuit board 
has
{ HEAD ~ The circuit board } has { TAIL ~ a groove } in a section of a surface of the circuit board
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH