Specifies the characteristics of a 90-mm (3.54-in) optical disk cartridge (ODC) of the type providing for information to be written, read, and erased many times, using thermomagnetic and magneto-optical effect. A part or all of the optical disk may be prerecorded (read only) and be reproduced by embossing information in the recording layer. This information is read without recourse to the magneto-optical effect. The optical disk cartridge consists of two parts, a protective case and an optical disk held inside the case. The optical disk shall be single-sided with one substrate and one recording layer.