No, I mean "different to" as how the UK formed was actually no different to how France, Spain or Germany formed, for example.
I am actually correct in law - domestic and international. The official term the UK Government and institutions use is Constituent Part. This* *is another way of saying region of the UK.
We do use the term "devolved" which is clear those areas are very much territory belonging to the Sovereign State known as the United Kingdom. Since they're part of the UK State, they're also regions of the UK itself.
There is no real need to state "the region of..." in speech in Parliament since the understanding is already there each part is a region of the UK itself.
Nor is there any real need to do so in informal speech.
But the position is clear - England, Scotland, Wales and Northern Ireland are NOT sovereign countries and their respective identities are, therefore, not nationalities.
That's why the Sovereign Power designates us all as British as per 1981 British Nationality Act.
In the UK census, you're simply asked how you would describe your national identity. This is not the same thing as the Sovereign Power agreeing the English, Scottish, Welsh and Northern Irish are nationalities as much as British. They definitely don't accept that which is clear from our passports, for example.
We still come back to England, Scotland, Wales and Northern Ireland all being regions of the United Kingdom itself.