first storing {HEAD ~ means} for holding {TAIL ~ written data} while the power is being supplied from a power source 
for holding
first storing { HEAD ~ means } for holding { TAIL ~ written data } while the power is being supplied from a power source
OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH