The TES sectors are similar to the previous NC sectors and the DESNZ has published a mapping between the two sector definitions (DESNZ).
Mae'r sectorau Ystadegau Allyriadau Tiriogaethol yn debyg i'r sectorau Cyfathrebu Cenedlaethol blaenorol ac mae'r DESNZ wedi cyhoeddi mapio rhwng diffiniadau'r ddau sector (DESNZ).