Z3 represents {HEAD ~ the atoms} necessary to complete {TAIL ~ a mono or bicyclic aromatic or heterocyclic ting system} containing 5 to 10 ring atoms and C is in an ortho or para position relative to W 
necessary to complete
Z3 represents { HEAD ~ the atoms } necessary to complete { TAIL ~ a mono or bicyclic aromatic or heterocyclic ting system } containing 5 to 10 ring atoms and C is in an ortho or para position relative to W
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH