The Netherlands is celebrating the 40th anniversary of the .nl country-code internet domain, which was approved on 25 April 1986 following a request by Piet Beertema, a systems administrator at the Centrum Wiskunde & Informatica (CWI), the Dutch national research institute for mathematics and computer science. Beertema and his colleague Teus Hagen conceived the idea for national European domains — including .nl and .be — on a beer mat, basing them on existing vehicle licence-plate country codes, and Beertema personally managed all registrations before the domain's administration was transferred to the foundation SIDN in 1996. Today more than six million .nl domain names are registered, placing the Netherlands fourth globally among country-code domains — a scale Beertema himself once described as having "gotten a little out of hand."