Abstract: The object of the present invention is to make an appropriate determination of whether recording is prohibited or not depending on the type of record/reproduce apparatus. To achieve the object, optical disk 1 of the present invention that can record or reproduce information through irradiation with laser light comprises a recording area 6 for recording the information, and a management area for recording management information of the optical disk 1, wherein the management area includes a recordable write-inhibit flag area 7 with a record/reproduce apparatus, and at least two types of the identifying information that are independent one another and identify whether recording is prohibited or not respectively for at least two recording linear velocities are recorded in the write-inhibit flag area 7.

Abstract: A grip member has a grip proper (1) made of a shape-memory resin in the shape of a bar, a connecting pin (4) disposed in one terminal part of the grip proper, a forked part (3) formed integrally in the other terminal side of the grip proper, and an annular part (2) formed integrally slightly toward one end of the grip proper (1) and adapted for enabling the forked part (3) to twine thereon. The grip member is enabled to cope easily with a delicate change in the gripping condition by heating the grip proper (1) and the vicinity thereof to a temperature surpassing the glass transition point of the shape-memory resin thereby endowing the shape-memory rubber with a rubbery state, causing the forked part (3) to twine itself around the annular part (2) in such a manner as to impart the shape of a loop to the grip proper.