The International System of Units (SI) (7^th ed., 1998)

The ISO (International Organization for Standardization) standards

• ISO 639:1988. Code for the representation of names of languages
• ISO 3166-1:1997. Codes for the representation of names of countries and their subdivisions -- Part 1: Country codes.
• ISO 3166 English country names and code elements: http://www.din.de/gremien/nas/nabd/iso3166ma/codlstp1/en_listp1.html
• ISO 8601:2000. Data elements and interchange formats - Information interchange - Representation of dates and times.
• ISO 11180:1993. Postal addressing

The ITU (International Telecommunication Union) standards

• ITU-T (http://www.itu.int) Recommendation E.123. Notation for national and international telephone numbers.
• List of ITU-T Recommendation E.164 assigned country codes:http://www.itu.int/itudoc/itu-t/ob-lists/icc/e164_717.html