ATVEF - (Advanced Television Enhancement Forum) - A former alliance of companies and concerns representing the broadcast and cable networks, television entities, consumer electronics, PC industries and more.  ATVEF’s primary area of interest was interactive television and they set standards related to it.  One aim was to aid in extending the Internet to broadcast media. ATVEF-compliant systems didn't need to be fully digital and thus could/can include the use of the Vertical Blanking Interval (VBI). ATVEF closed at the end of 1999 and turned over the specification to the ATV Forum and SMPTE.

For more information on the ATVEF contact The ITV Alliance.
Also see informitv &

https://en.wikipedia.org/wiki/SMPTE