In order to further facilitate {TAIL ~ the inventions ease} of {HEAD ~ use}, the sub columns on the visual display area 14 may be color keyed to indicate BC or NCB 
In order to further facilitate { TAIL ~ the inventions ease } of { HEAD ~ use } , the sub columns on the visual display area 14 may be color keyed to indicate BC or NCB
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH