The basic technology of Ceefax remained compatible with the 1976 unified rollout; system elaborations in later years were made such that earlier receivers were still able to do a basic decode of pages, but would simply ignore enhanced information rather than showing corrupted data.
Teknologi dasar Ceefax tetap kompatibel dengan peluncuran 1976 bersatu; elaborasi sistem sejak itu telah dibuat sedemikian rupa sehingga penerima sebelumnya masih bisa melakukan decode dasar halaman, tetapi hanya akan mengabaikan informasi ditingkatkan daripada menunjukkan data yang rusak.