Applies to magnetic video recording and/or playback with 8 mm tape cassettes on two-head helical-scan video cassette recorders, suitable for the recording and/or playback of monochrome as well as colour television signals. Defines the electrical and mechanical characteristics of equipment which will provide for interchangeability of recorded cassettes, including the ability to reproduce recordings made on both types of magnetic tapes defined in section 2. Related to 525 line / 60 field or 625 line / 50 field systems, NTSC and PAL respectively.