Recordable optical disk

A recording apparatus for recording information to an optical disk having a main information area in which data information is recordable in a recording layer of a groove having a wobble such that said data information is readable using a light, a control data area located at an inner periphery side with respect to said main information area, and a sub information area, wherein in said control data area, other information including first physical format information has been previously recorded at a predetermined position instead of key information used to decipher the data information, said sub information area being configured to store second physical format information with an information structure which differs from an information structure of said control data area, comprising:

• a pickup that records data to said optical disk and reads recorded signals from said optical disk;
• a first controller that controls a movement of said pickup;
• a second controller that controls a reproducing operation of data read from the optical disk;
• and
• a third controller that structures data to be recorded to said optical disk, wherein said third controller controls a recording of second physical format information to said sub information area with an information structure different from an information structure of said control data area.