The reason this exists is that the Dutch Government is forcing municipalities to put every address/building into a central database, the "Basisregistratie Adres

The reason this exists is that the Dutch Government is forcing municipalities to put every address/building into a central database, the "Basisregistratie Adressen en Gebouwen"(BAG, "Registration of addresses and building") It has uncovered some interesting issues with addresses - some student housing for instance has complicated numbering schemes that don't fit in the database (i.e 10 B 5). Municipalities that don't cooperate are cut national contributions.