They're saying, I think, that if you're going to have a referendum on independence, ever citizen of the existing state should vote, not just members of the prop

They're saying, I think, that if you're going to have a referendum on independence, ever citizen of the existing state should vote, not just members of the proposed state. Otherwise, you could just have thousands of tiny groups of people each declaring their own independent state. As a UK citizen, I would have preferred it if our recent referendum had been voted on by all members of the EU, rather than just British citizens.