No. Anybody can write a document.
It needs to be recognized, if challenged to be legal.
Self-governance is a right, unless challenged.
Then if it is not recognized, it ceases to be a right as their right was subsumed under the rights of the larger body. And yet, do they not still have that right even if it’s been removed from them ?
It’s community based. All contracts are and a national founding document is a contract.