> Even if nothing changes, you can run into trouble. Norwegian PNs have your birth date (in DDMMYY format) as the first six digits. Surely that doesn't change, right?

I guess that Norway has solved it in the same or similar way as Sweden? So a person is identified by the PNR and for those systems that need to track a person over several PNR (government agencies) use PRI. And a PRI is just the first PNR assigned to a person with a 1 inserted in the middle. If that PRI is occupied, use a 2,and so on.

PRI could of course have been a UUID instead.