An information layer 0 comprises a system lead-in area, data lead-in area,
data area, and middle area, an information layer 1 comprises a system
lead-out area, data lead-out area, data area, and middle area, an end
position of the data area of layer 1 is positioned outer than a start
position of the data area of layer 0, the data lead-in area comprises a
guard track zone wider than a test zone in the data lead-out area, the
data lead-out area comprises a guard track zone wider than a test zone
and a management zone in the data lead-in area, the middle area of layer
0 comprises a guard track zone wider than a test zone in the middle area
of layer 1, and the middle area of layer 1 comprises a blank zone wider
than a test zone in the middle area of layer 0.