scope:

This European Standard (Telecommunications series) is applicable to 625-line PAL and SECAM systems in use, in case, where wide screen signalling is required by the broadcasters. It specifies the wide screen signalling information, the coding and the way of incorporating the coded information into a 625-line system. The wide screen signalling information contains information on the aspect ratio range of the transmitted signal and its position, on the position of the subtitles and on the camera/film mode. Furthermore signalling for EDTV and for surround sound is included. Some bits are reserved for future use.