A1 Global Admininistrative Unit Layers en A2 UN Second Administrative Level Boundary Project en Note: the unsalb.org website is no longer accessible, and public access to the boundaries resources has been removed http://www.ungiwg.org/content/united-nations-international-and-administrative-boundaries-resources A3 Global Administrative Areas en A4 ISO Country (3166-1 alpha-2) en G1 Geonames en G2 OpenStreetMap en Note: the code should be formed by prefixing the relevant OpenStreetMap ID with node/ way/ or relation/ as appropriate, e.g. node/1234567