{TAIL ~ A predetermined number} of pilot holes 164 may be drilled into the side edge 48 of the inactive door 24 at {HEAD ~ several predetermined locations} 
{ TAIL ~ A predetermined number } of pilot holes 164 may be drilled into the side edge 48 of the inactive door 24 at { HEAD ~ several predetermined locations }
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD