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 in the USA. A few other services were offered by some large-market TV stations in the US throughout the 1980s, such as Metrotext from KTTV in Los Angeles and KeyFax from WFLD in Chicago. Despite this, the system never caught on in the USA partly due to EIA-608 being deployed for captioning before Teletext was introduced and the higher cost of Teletext receivers. In the 1980s a similar system called Telidon was developed in Canada by the Department of Communications. It used a simple graphics language that would allow a more complex circuit in the TV to decode not only