Why bother coding TV into your RNS-D?

[HPsauce]

What does it achieve, if anything?

I ask because I'm in the process of fitting a DVB-T tuner to mine, an S8 that did NOT have any sort of TV installed.

I already have a DVB-T tuner but it just has standard outputs, so I bought an interface box (T-ERA one) and today got around to wiring it in. It works, tested with video input from a video camera. (I haven't quite decided where the tuner box will sit)

One thing I did notice was that no volume display appeared overlaid on the screen when turning the volume knob. In fact I wasn't even sure the volume was changing, but later I think I decided it seemed to use the Radio volume. (My DVB-T tuner has its own volume control so hopefully this won't be a problem.)

At that stage I wondered if that was because it wasn't coded. Checking the status (down arrow and AS pressed together) it showed no TV so I coded it in (Navigation, Adaptation channel 7 changed from 0 to 4).

After doing that everything still worked, exactly the same, the only difference was that checking the status it now showed TV OK. I can still only select the TV input if it is working properly.

So, given that the RNS-D detected and allowed me to select the TV/Video input, does anyone know what the coding is actually for?