Initials for the National Television System Committee (USA), also stands for ‘Never Twice the Same Colour’.
1. The ‘NTSC-Committe I’ during 1941 established the 525line / 60Hz 2:1 interlaced monochrome television in the U.S.
2. The NTSC- Committee II during 1953 established the 525line / 59.94Hz 2:1 interlaced composite color format television in the U.S. with two color-difference signals [labeled / and Q ] quadrature-modulated onto a color subcarrier, and added to the luminance signal.
3. ‘NTSC’ is often used as the convenient name for the current North American television system. PAL is used in Australia.
1964, SMPTE Nomenclature for Motion Picture Film used in Studios and Processing Laboratories, Society of Motion Picture and Television Engineers, USA SMPTE Glossary http://www.smpte.org/home/