National Patient Identifier: this is an example of a National Citizen Identifier used in health care. It is the real Dutch "Burgerservicenummer", the Citizen Service Numnber. The Burgerservicenummer (BSN) is a unique personal number issued to everyone registered in the 'Gemeentelijke Basisadministratie persoonsgegevens' (GBA), or the Personal Records Database of the municipality. The BSN was formerly known as the Social-Fiscal (So-Fi) number.

(Citation: http://www.denhaag.nl/en/residents/to/Burgerservicenummer-BSN.htm)

It has the following format: 9N, with preceding zeros if shorter than 9 characters.