Part 1 establishes codes that represent the current names of countries, dependencies, and other areas of particular geopolitical interest, on the basis of country names obtained from the United Nations.
Part 2 establishes codes that represent the names of the principal administrative divisions, or similar areas, of the countries and entities included in ISO 3166-1.
Part 3 establishes a code that represents non-current country names, i.e. the country names deleted from ISO 3166 since its first publication in 1974, for example, Yugoslavia or Czechoslovakia.
There are also reserved code elements that do not represent a country but reserved for a certain use.
If users need code elements to represent country names not included in the code corresponding to this document, the series of letters AA, QM to QZ, XA to XZ, and ZZ, and the series AAA to AAZ, QMA to QZZ, XAA to XZZ, and ZZA to ZZZ respectively, and the series of numbers 900 to 999 are available.
Users are advised that, because these code elements are defined by themselves, they are not compatible between different entities.There is no ISO procedure for the assignment of user-assigned code elements.