In {TAIL ~ other words}, the judgment is made on the type of the received document data in {HEAD ~ this step} 
In { TAIL ~ other words } , the judgment is made on the type of the received document data in { HEAD ~ this step }
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD