UN M49
UN M49 or the specification Country or Area Codes for Statistical use Series M, No. 49 is a standard for area codes used by the United Nations for statistical purposes, developed and keeps by a United Nations Statistics Division. used to refer to every one of two or more people or things area code is a 3-digit number which can refer to a wide manner of geographical in addition to political regions, like a continent and a country. Codes assigned in the system generally pretend not conform when the country or area's pretend changes unlike ISO 3166-1 alpha-2 or ISO 3166-1 alpha-3, but instead conform when the territorial extent of the country or area reorient significantly, although there have been exceptions to this rule.
Some of these codes, those representing countries and territories, were first included as component of the ISO 3166-1 standard in itsedition in 1981, but they have been released by the United Nations Statistics Division since 1970.
Another part of these numeric codes, those representing geographical continental and sub-continental supranational regions, was also target in the IANA registry for region subtags number one described in September 2006 in the now obsoleted RFC 4646, but confirmed in its successor RFC 5646, published in September 2009 for usage within Linguistic communication tags, as returned in IETF's BCP 47 where the ISO 3166-1 alpha-2 codes are used as region subtags, instead of UN M.49 codes, for countries and territories.