Teletext systems the country being closed captioning, TV Guide On Screen, and Extended Data Services (XDS). A version of the European teletext standard designed to work with the NTSC television standard used in North America was first demonstrated in the US in 1978 by station KSL in Salt Lake City, Utah, premiered a teletext service using Ceefax. They were followed by American television network CBS, which decided to try both the British Ceefax and French Antiope software for preliminary tryouts for a teletext service, using station KMOX (now KMOV) in St. Louis, Missouri as a testing ground. CBS decided on Antiope and
Teletext systems as the "Broadcast Teletext Specification". With some tweaks to allow for alternative national character sets, and adaptations to the NTSC 525-line system as necessary, this was then promoted internationally as "World System Teletext". It was accepted by CCIR in 1986 as "CCIR Teletext System B", one of four recognised standards for teletext worldwide. In France, where the SECAM standard is used in television broadcasting, a teletext system was developed in the late 1970s under the name "Antiope". It had a higher data rate and was capable of dynamic page sizes, allowing more sophisticated graphics. It was phased out in favour