Patent ID: 7724629

Claim:
An information storage medium for use with a recording and/or reproducing apparatus, the information storage medium comprising: a user data area comprising a plurality of user data frames, each of the user data frames comprising corresponding sync data of a plurality of sync data; and an additional data area located before and/or after the user data area, and comprising at least two additional data frames, a first one of the additional data frames comprising first sync data, and a second one of the additional data frames comprising second sync data, the first sync data and the second sync data being different from the plurality of sync data of the user data frames, the first sync data and the second sync data enabling the apparatus to identify the additional data area from the user data area when the information storage medium is used with the apparatus; wherein: the first sync data comprises a first sync body and a first sync identification, the second sync data comprises a second sync body and a second sync identification, the first sync identification is different from the second sync identification, the information storage medium is a read-only information storage medium, and the additional data area makes the read-only information storage medium compatible with a recordable information storage medium.