On {TAIL ~ the basis} of {HEAD ~ extra character registration information}, whether bit map data is compressed or not is judged 
On { TAIL ~ the basis } of { HEAD ~ extra character registration information } , whether bit map data is compressed or not is judged
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH