Article 9 of the National Interoperability Framework (Royal Decree 4/2010) stipulates that public authorities: "... will keep an updated repository on administrative bodies and registration offices for citizens, as well as the relations between them. These bodies and offices will be coded uniquely and this codification will be disseminated to the public authorities. "
The Common Directory of Organic Units and Offices provides a unified and common Inventory to all public administrations, including the relationship of the organizational units and their associated offices, assigning a unique coding to them. The directory facilitates the distributed and co-responsible maintaining of the information for all public administrations involved.
The existence of the directory is key for the administrations interoperability since the head of a procedure or a basic registration unit can be uniquely specified from the recipient of a registration or an electronic invoice exchange.