"Teletext" in this context is a signalling protocol for transmitting text content over PAL TV, for decoding by an appropriate receiver.

The BBC's service was branded "Ceefax", ITV and Channel 4 branded theirs "Teletext".

The current 'red button' service is a completely different protocol running on DVB (Digital Video Broadcast, i.e. digital TV). Text packets are added to the MPEG-2 stream.

FWIW you can still get Teletext over MPEG TS (DVB or IPTV), it's just already de-modulated, but even error correction bits are still there (and are useless).

In France most IPTV operators still use teletext for live subtitling because it eats much less bandwidth than dvbsub

Ah, my apologies then. My confusion was that I didn't think there was a difference between the current mechanism and the old one.

The ITV/C4 service was originally Oracle; this was later replaced by “Teletext Ltd”.

https://en.m.wikipedia.org/wiki/ORACLE_(teletext)

They’re not the same and I don’t think they’ve ever been synonymous with each other (or at least not by people who work in the Broadcasting industry).

Red Button is the service that replaced teletext/ceefax in 2012. Teletext was an analogue service, Red button was a whole new digital service offering similar information, it’s entirely different infrastructure underneath, it’s not just a “lick of paint”.

You're right. My bad. I worked on a modernisation project for the DVB version of this in 2018. Internally we used to refer to it as Teletext, hence my confusion.

> Teletext was an analogue service

Teletext was a _digital_ service provided over an _analogue_ bearer - the modulation of the signal is continuous, not discrete.

Teletext/Ceefax has been dead since the analog switch-off in 2012. Red Button uses MHEG-5.