Country code

Map of Oceania with country codes.

Country codes are alphabetic or numeric short codes created to represent countries and their dependent areas, for use in data processing and communications. The most widespread system is ISO 3166-1.

ISO 3166-1

For most of the countries of the world, and their dependent territories, this standard defines:

• a two-letter code (ISO 3166-1 alfa-2)
• a code of three letters (ISO 3166-1 alfa-3)
• a numerical code of three figures (ISO 3166-1 numerical)

The two-letter code is used as the base for some other code or application, such as:

• in ISO 4217 foreign exchange codes.
• in country codes of top-level Internet domain names: list of Internet domains.

Other country codes

• The three-letter codes of the International Olympic Committee (IOC), which are used in sports testing: list of national IOC codes
• FIFA has also implemented a three-letter code system.
• The encoding system for registration plates under the 1949 and 1968 United Nations Convention on Roded Traffic (other than signs of vehicles in international traffic): list of codes of international registration plates
• The two-letter codes of the Federal Standard for the Information Processing (Federal Information Processing Standard, FIPS) used by the US government and the CIA World Factbook
• International Telecommunication Union (ITU):
  • 1-3 international telephone codes E.164: list of telephone codes,
  • country codes for mobile (mobile country codes, MCC) for mobile phone addresses/without threads,
  • the first characters of the call signals in the radio stations (marítima, aeronautics, radio, radio broadcasting, etc.) define the country: the ITU prefixes,
  • the codes of member countries the ITU in letters,
  • the codes of three figures used to identify countries in the marine mobile radios, called maritime identification number
• European Union:
  • Until the enlargement of the European Union of 2004 the EU used the UN Conventions on Traffic for registration codes; since then, it uses the ISO 3166-1 codes, with two exceptions: THE (and not) GR) is used for Greece, and UK (and not) GB) is used for the UK. [1]
  • The Nomenclature of Statistical Territorial Units (NUTS), which deals mainly with subdivisions of EU member states.
• International Civil Aviation Organization (ICAO)
  • Prefixes of aircraft registration,
  • nationality letters for localization indicators.

The developers of ISO 3166 intend that it will eventually replace other existing identification codes.

Other encodings

The following can represent countries:

• Initial ISBN numbers are identifiers for countries, areas, or linguistic regions.
• The first three figures of the article number in the EAN-UCC barcodes