ISO/IEC 13481:1993

Specifies two implementations: Type R/W (data to be written, read and erased many times) and type WO (having write once, read multiple functionality). Specifies the conditions for conformance testing and the reference drive; the environments in which the cartridges are to be operated and stored; the mechanical, physical and dimensional characteristics of the case and of the cartridge; the format of the information on the disk; the characteristics of the embossed information on the disk; the magneto-optical characteristics of the disk; the minimum quality of user-written data on the disk.