Optical disk, recording apparatus and playing apparatus

摘要

An optical disk (10), a recording apparatus and playing apparatus which can record various kinds of identification information in the form of a pit train (11) and a bar code (12) without decreasing the data recording area for main information. Both a first data block including a pit train indicating first identification information and a second data block including a bar code indicating second identification information are formed in the recording part at the same radius.