"This International Standard defines the characteristics of 90 mm Optical Disk Cartridges (ODC) with a capacity of 1@3 GB per cartridge. It specifies only Type R/W for 2 048?Cbyte sectors of such cartridges. Type R/W provides for data to be written@ read and erased many times over the entire recording surface of the disk using the thermo-magnetic and magneto-optical effects. It is also referred to as ""fully rewritable"". This International Standard provides for 2 048-byte sectors only. All sectors on a disk are of the same size. This International Standard specifies: - the conditions for conformance testing and the Reference Drive; - the environments in which the cartridges are to be operated and stored; - the mechanical and physical characteristics of the cartridge@ so as to provide mechanical interchange ability between data processing systems; - the format of the information on the disk@ both embossed and user-written; including the physical disposition of the tracks and sectors@ the error correction codes@ and the modulation method used; - the characteristics of the embossed information on the disk; - the magneto-optical characteristics of the disk@ enabling processing systems to write data onto the disk; - the minimum quality of user-written data on the disk@ enabling data processing systems to read data from the disk. This International Standard provides for interchange between optical disk drives. Together with a standard for volume and file structure@ it provides for full data interchange between data processing systems. "