ISO 3166 is the international standard for codes representing countries and their subdivisions. ISO 3166-1 defines the alpha-2, alpha-3 and numeric country codes; ISO 3166-2 covers subdivisions. Codes are maintained by the ISO 3166 Maintenance Agency.
ISO 3166
ISO 3166-1 is the reason US, DE and JP mean the same thing everywhere: two-letter (alpha-2), three-letter (alpha-3) and numeric codes for countries, with ISO 3166-2 extending them to subdivisions. The ISO 3166 Maintenance Agency maintains the code lists; the numeric codes come from the United Nations.
Business layer
The API Commons eligibility schema expresses the countries a provider serves or restricts as ISO 3166-1 codes, so availability can be compared across providers. See The Technical Side Translated. The Business Side Did Not.
Industry: cross-domain
