{HEAD ~ The support} 2 wherein {TAIL ~ the envelope} of one support can be stacked on the envelope of another support and used in multiple 
wherein
{ HEAD ~ The support } 2 wherein { TAIL ~ the envelope } of one support can be stacked on the envelope of another support and used in multiple
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH