scope:

This ECMA Standard specifies the characteristics of 130 mm optical disk cartridges (ODCs) with a capacity of 1 Gigabyte per cartridge. The Standard specifies two related, but different implementations of such cartridges: Type R/W Provides for data to be written, read and erased many times over the whole of both recording surfaces of the disk using the thermo-magnetic and magneto-optical effects. Type WO Provides write once, read multiple functionality on both disk surfaces using the thermo-magnetic and magneto-optical effects.