<p>An optical disc (100) is provided with a recording region where prescribed clock information (WBL) is preformatted for recording. The clock information is (i) included in a first frequency band that is definable by a first reference frequency (Fstd) (that is impossible for a conventional reproducing device to detect by a detecting method based on a self-correlation) and is (ii) defined by a frequency that is integer times the first frequency.</p>
