Dev Registration - Which Marketplaces?


I think this question is really “in which unique seller central sites are unique developer id’s actually defined”, but here’s the underlying issue - when you register or update a developer profile in UK, and you get to pick any marketplace id, globally. But I know those developer id’s in the UK don’t work in north america, for example but do in EU… so if I want access to UK+EU, I know I can actually just get a seller central UK developer id…and picking .com doesn’t do anything… but I still don’t know which seller central sites to apply in be able to be global… and I know it’s not all of them.