[Stuart]

Yes, the difference is that BBC regions are actually on the EPG - whereas ITV regions are only accessible via the right number.

ITV1/STV regions can be added using the 'Add Channels' function.

The difference is that because of the TVL, all BBC services have to be available to everyone across all platforms on which they are broadcast nationally.

The exceptions are DTT/DCab where you automatically receive only your allocated regional service. They are not nationally distributed.

Because all regional services are broadcast on DSat they are required to allow access to all of them. I may have over simplified that explanation, but I'm sure that's how it was given originally.