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