A signal having {TAIL ~ a predetermined pattern} is written in {HEAD ~ a predetermined region} of an optical disc at a plurality of different write power levels Pwm 
A signal having { TAIL ~ a predetermined pattern } is written in { HEAD ~ a predetermined region } of an optical disc at a plurality of different write power levels Pwm
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH