There are numerous sources detailing and defining HK/China Euro exclusives. It is very clear that something like mountain boys or night light were never avalable in North America. Nothing like this exists for North American exclusives. Even something like Wiki it's not clear if a pony was exclusive and I know of no difinitave list. So... should there be such a list? Not trying to be a troll, just tossing ideas out there.
Ironically I think my site may be the only site which actually does tackle those things, because I list on every pony/set whether it was sold globally, in the UK, Europe, US/Canada and if I know, for other places in the world as well. I don't know definitively with the Australian issue or some other places like South Africa and Europe is a constantly changing picture because they're not identical markets. So the information is on my page. But my page is a site born from the concept of UK pony history and then branched outwards, so I don't think it's the first place US collectors think to go to look to find out their exclusives
I think it's also not as simple as some folk realise to differentiate. Some of the best known 'US' ponies, like Mimic, were sold not in the UK or much of Europe but were definitely in Italy. Munchy and Yum Yum weren't in the UK either, but were definitely in the Netherlands. I've been told categorically by a Dutch collector that pearly baby sea ponies weren't sold there, but I have two US ones mint on Dutch cards which neither she nor I can explain at present. And so on it goes. Pony packaging and stuff like that is my Nirvana, so I'm all interested in this stuff, but I can imagine anyone else running an ID site looking at the mess and going...nah. It's rather like Pandora's Box.
I don't think it was a case you struck a nerve, I just think that PKW was answering a different issue, which was about the definition of Nirvana and how it came to be.