a first surface optical disk is disclosed that has machine readable code information , such as bar code information , disposed thereon to permit a disk drive or other device to obtain certain basic information regarding the disk in an efficient and reliable manner . the machine readable code may include error detection and error correction code to correct errors , such as those caused by surface dust , that may arise during reading the machine readable code . the machine readable code may be disposed within a portion of a ring on the optical disk . human readable alphanumeric characters , including graphics , identifying the side of the optical disk and other basic information may also be disposed within the ring .