Teletext systems network in the mid-late 1970s. Due to the adoption of a common teletext standard (WST), the ORACLE system ceased in 1976. The name was retained for the service itself, that continued after that year using the WST standard. "World System Teletext" (or "WST") is the name of a standard for teletext throughout Europe today. Almost all television sets sold in Europe since the early ’80s have built-in WST-standard teletext decoders as a feature. It originally stems from the UK standards developed by the BBC (Ceefax) and the UK Independent Broadcasting Authority (ORACLE) in 1974 for teletext transmission, extended in 1976
Teletext Services (XDS). NABTS was originally developed as a protocol by the Canadian Department of Communications, with their industry partner Norpak, for the Telidon system. It was similar to the European World System Teletext (WST, aka CCIR Teletext System B), but differences between the European and North American television standards and the greater flexibility of the Telidon standard led to the creation of a new delivery mechanism that was tuned for speed. First demonstrated in the United States in 1978, NABTS was the standard used for both CBS's ExtraVision and NBC's very short-lived NBC Teletext services in the mid-1980s. Station KSL-TV