This International Standard applies to magnetic video recording and/or reproduction using 12,65 mm (0,5 in) tape cassettes on helical-scan video cassette recorders suitable for broadcast applications. This standard specifies two recording modes. MODE I uses oxide particle tape, MODE II uses metal particle tape and permits frequency modulated (FM) audio signals to be recorded. The standard defines the electrical and mechanical characteristics of equipment which will provide for interchangeability of recorded casse ttes. The requirements given are related to 525 line-60 field and/or 625 line-50 field systems.