An optical disk has a central axis and a major face extending in a radial direction from the central axis. The optical disk is rotatable around the central axis at an angular velocity and is formed with a recording layer on the major face. The recording layer is optically recordable with information and is formed with a track area containing tracks which are arranged at a predetermined track pitch in the radial direction and which are accessable by an optical beam to read or write information while the tracks move at a linear velocity relative to the optical beam. The recording layer is preliminarily recorded with control information indicative of the predetermined track pitch and/or either of a predetermined linear velocity of the tracks or a predetermined angular velocity of the disk. The control information is readily readable from the recording layer to facilitate the accessing of the tracks by the optical beam.