Applies to magnetic recording of one digital video and four digital audio signals using 19 mm tape cassettes. Is valid for TV signals in digital component form, generated according to the rules of CCIR Recommendations 601 and 656 and for digital audio signals according to IEC 60958. Also describes the digital recording of ancillary data and the analogue recording of one cue track and the control track. Defines the electrical and mechanical characteristics of equipment which will provide for the interchangeability of recorded cassettes. The requirements given relate to 525/60 and 625/50 TV systems.