{HEAD ~ The passageway} includes {TAIL ~ a fuel delivery end} located in a firebox and a fuel infeed end below the plate 
{ HEAD ~ The passageway } includes { TAIL ~ a fuel delivery end } located in a firebox and a fuel infeed end below the plate
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH