This International Standard specifies the physical and magnetic characteristics of a 12, 7 mm wide, 48-track magnetic tape cartridge, to enable interchangeability of such cartridges. It also specifies the quality of the recorded signals, a format - called Digital Linear Tape 1 (DLT 1) - and a recording method. Together with a labelling standard, e.g. ISO 1001, it allows full data interchange by means of such magnetic tape cartridges.