Outlines the characteristics of a 6.30 mm (0, 25 in) magnetic tape cartridges intended for data interchange and physical interchangeability between information processing systems utilizing the ISO 7-bit coded character set (ISO 646), its extensions (ISO 2022) and/or 8-bit character set (ISO 4873). The cartidge is of the twin-hub coplanar type, loaded with 6, 30 mm (0, 25 in) magnetic tape tor digital recording using the 53 bpmm (1600 bpi) phase-encoding method.