CCIR System M

[9] System M comprises a total of 525 interlaced lines of video, of which 486 contain the image information, at 30 frames per second.

[10] It was also adopted in the Americas and Caribbean; Myanmar, Philippines, South Korea, Taiwan and Japan (here with minor differences, informally referred to as System J).

This combination is called NTSC-M, but usually simply referred to as "NTSC", because of the relative lack of importance of black-and-white television.

Between 1970 and 1991 a variation of the SECAM color system, known as SECAM-M, was used in Cambodia,[14] Laos, and Vietnam (Hanoi and other northern cities).

[15][17] Developed to improve analog NTSC,[18] it adds features like progressive scan, ghost cancellation and widescreen image format.

Analog TV systems global map, with System M in red.
Television color encoding by nation: Brazil ( PAL-M ) and all green countries ( NTSC ) are based on monochrome System M.