International vehicle registration code

Since the Vienna Convention on Road Traffic entered into force on 21 May 1977, in signatory countries it replaces previous road traffic conventions, including the Geneva Convention on Road Traffic, in accordance with its Article 48. According to the Vienna Convention on Road Traffic, the distinguishing sign of the country of registration must be displayed on the rear of the vehicle. The sign may either be placed separately from the registration plate as a white oval plate or sticker, or be incorporated in the vehicle registration plate. When the distinguishing sign is incorporated in the registration plate, it must also appear on the front registration plate of the vehicle.

The requirement to display a separate distinguishing sign is not necessary within the European Economic Area, for vehicles with license plates in the common EU format, which satisfy the requirements of the Vienna Convention, and so are also valid in non-EU countries signatory to that convention.[9] Separate signs are also not needed for Canada, Mexico and the United States, where the province, state or district of registration is usually embossed or surface-printed on the vehicle registration plate.

Car with Palestinian license plate, bearing Latin letter "P" and Arabic letter Fāʼ.

The unofficial code for Brittany, Bzh

There are unofficial codes in common use, such as "AS" for Asturias, "CAT" for Catalonia, "SCO" for Scotland, "CYM" for Wales (Welsh Cymru), "BZH" for Brittany (Breizh), FRL for Friesland, "VL" for Flanders (Vlaanderen), "V" for Vojvodina/Vajdaság, "TS" for Transylvania, "P" for Palestine, "PR" for Puerto Rico, "CSB" for Kashubia (Cassubia) and "SIC" for Székely Land (from Latin Terra Siculorum). Some of these, such as "VL" which is used by Flemish separatists, are used despite being specifically illegal under local laws.

In addition, in some areas, vehicle-style stickers have been used to denote and promote other entities, such as towns, islands, businesses, and even associations. These irregular stickers almost always bear an explanation of the code in small print near the edge of the sticker, as the codes used may be unfamiliar.

A separate system is used for vehicles belonging to the diplomats of foreign countries with license plates from the host country. That system is host country-specific and varies largely from country to country. For example, TR on a diplomatic car in the USA indicates Italian, not Turkish. Such markings in other countries (e.g. Norway) are indicated with numbers only, again different from international standards (e.g. 90 means Slovakia in Norway).

• Aircraft registration
• International Driving Permit
• ISO 3166
• Vienna Convention on Road Traffic
• Vehicle identification number

• "RPW": Neil Parker and John Weeks, Registration Plates of the World, Europlate; 4th edition (2004)

Wikimedia Commons has media related to International vehicle registration codes.

• Distinguishing Signs of Vehicles, UNECE
• Distinguishing Signs used on Vehicles in International Traffic Notified to the Secretary General of the United Nations, UNECE
• Convention on Road Traffic, Geneva, United Nations Treaty Collection
• Convention on Road Traffic, Vienna, United Nations Treaty Collection
• UN Economic Commission for Europe, Working Party on Road Transport (WP.11)
• Miscellaneous Proposals of Amendments to the Model Regulations on the Transport of Dangerous Goods: Identification of Approval Country in Marking, UN/SCETDG/33/INF.5 (table compares ISO 3166 and DSIT codes)
• Association Francoplaque: Collectionneurs de Plaques d'Immatriculation (data mostly from RPW, above)
• European Registration Plate Association: Registration Plates of the World Online (registration required; data mostly from RPW, above)