Teletext and to pad out the fixed packet. The vertical caption position is determined by the packet address. In the case of the Ceefax and ORACLE systems and their successors in the UK, the teletext signal is transmitted as part of the ordinary analog TV signal but concealed from view in the Vertical Blanking Interval (VBI) television lines which do not carry picture information. The teletext signal is digitally coded as 45-byte packets, so the resulting rate is 7,175 bits per second per used lines (41 7-bit 'bytes' per line, on each of 25 frames per second). A teletext page comprises
Teletext systems as the "Broadcast Teletext Specification". With some tweaks to allow for alternative national character sets, and adaptations to the NTSC 525-line system as necessary, this was then promoted internationally as "World System Teletext". It was accepted by CCIR in 1986 as "CCIR Teletext System B", one of four recognised standards for teletext worldwide. In France, where the SECAM standard is used in television broadcasting, a teletext system was developed in the late 1970s under the name "Antiope". It had a higher data rate and was capable of dynamic page sizes, allowing more sophisticated graphics. It was phased out in favour