Child OIDs are the numeric country code (assigned by the United Nations (UN) Statistics Division) of each country with, as identifier, the corresponding two-letter alpha-2 code element of ISO 3166-1 (see the correspondence table between country codes and OIDs. Each child OID identifies the ISO Member Body in each country. Arcs below the "country code" are allocated by the registration authority nominated by a country to manage its country OID.
Note: The existence of a country code in ISO 3166 does not necessarily imply that there is an ISO Member Body for that country, or that the ISO Member Body for that country administers the country OID arc.