This part of IEC 60843 specifies a method of auxiliary data recording and playback with the IEC 60843 8 mm video system. This part is applicable to both 525 line - 60 field and 625 line - 50 field television systems.
IEC 60843-4:2000 history
2000IEC 60843-4:2000 Helical-scan video tape cassette system using 8 mm magnetic tape (8 mm video) - Part 4: Video subcode (VSC)