ISO 3166-1 alpha-2

[10][11] This notwithstanding, the Official Journal of the European Communities specified that GR and GB be used to represent Greece and United Kingdom respectively.

[12] For VAT administration purposes, the European Commission uses EL and GB for Greece and the United Kingdom respectively.

[13] IETF language tags (conforming to the BCP 47 standard track and maintained in an IANA registry) are also partially derived from ISO 3166-1 alpha-2 codes (for the region subtags).

The full list of ISO 3166-1 codes assigned to countries and territories are usable as region subtags.

Under the newer stability policies, old assigned codes that have been withdrawn from ISO 3166-1 should no longer be reassigned to another country or territory (as has occurred in the past for "CS").

The following is a complete list of the 249 current officially assigned ISO 3166-1 alpha-2 codes, with the following columns:[1] The United States Department of State uses the following user assigned alpha-2 codes for the nine territories, respectively, XB, XH, XQ, XU, XM, QM, XV, XL and QW.

The following alpha-2 codes can be user-assigned: AA, QM to QZ, XA to XZ, and ZZ.

For example, several codes are reserved because they are used for international intellectual property organizations in WIPO Standard ST.3.