1975-197?
197?-19??
Introduced before 1978.
19??-198?
Introduced before 1983.
198?-1991
Introduced before 1988. Was still used on the service breakdown page until Ceefax's demise in October 2012.
Introduced before 1978.
Introduced before 1983.
Introduced before 1988. Was still used on the service breakdown page until Ceefax's demise in October 2012.