"Let me look it up... okay, the most permissive station citizenship-wise is Hope Miller Sphere. They are still as long as they want their federated status obliged to keep birthright citizenship records - if a Stations citizen has a kid the kid is one too. They have to comply with emergency taxation, though Hope Miller Sphere doesn't do non-emergency taxes. System treaties about disease response, unlicensed summoning, WMDs, educational minima... okay, that might bite somebody, you have to teach your kids a few super basic things but that might be awkward with someone from Oerth. I don't know how much if any magic counts as a WMD. Uh, and no rape or murder or battery but they don't prosecute simple assault, theft... wow, I know where to go if I ever... okay, yeah, I think that's everything relevant."