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