World System Teletext

World System Teletext (or WST) is the name of the first successful standard for encoding and displaying teletext information, and is used as the standard for teletext throughout Europe today.

It originally stems from a standard developed by the European Conference of Postal and Telecommunications Administrations in 1974 called CEPT1, which drew out standards for videotex services. Some elements of CEPT1 were later used to form the WST standard. The official name for the current version of WST is "World System B".

Almost all television sets sold in Europe since the early 80s have built-in WST-standard teletext decoders as a feature.

WST is used for all teletext services in Europe & Scandinavia, including Ceefax from the BBC and services from Teletext on ITV in the United Kingdom, ZDFtext from ZDF and ARDText from ARD in Germany, and Tekst-TV from NRK in Norway, among many other teletext services offered by other television networks throughout the European continent.

WST in the United States

WST also saw some use in the United States in the 1980s, for the Electra service, which was carried on SuperStation WTBS (now TBS Superstation). It was also used for other teletext services on other television stations & networks in the USA as well.

Zenith in the US also included built-in WST teletext decoders in their higher-end models of TV sets, such as their "Digital System 3" line throughout the 1980s. Also, Dick Smith Electronics offered through their American distributors a WST teletext decoder in the form of a set-top box, which was sold as a kit.

This was all in competition to another teletext standard developed exclusively in North America, NABTS (North American Broadcast Teletext Standard). It was developed in Canada by Norpak, and was used by CBS for their ExtraVision service and for a very short time by NBC in the mid 1980s. However, NABTS never became as successful as WST in the American continent, since NABTS was a more advanced technology, which required a much more complicated and expensive decoder (even though it had improved graphics capability over WST).