Then, {HEAD ~ user data} is recorded in a part of the data area 324 of the second recording layer 302 along a scanning direction 532 to form {TAIL ~ a partial range} used data area 512 
Then , { HEAD ~ user data } is recorded in a part of the data area 324 of the second recording layer 302 along a scanning direction 532 to form { TAIL ~ a partial range } used data area 512
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH