Vehicle registration plates of Bulgaria compatible with both the Cyrillic and Latin alphabets came into force: Vehicle registration plates of Bulgaria Standard Bulgarian vehicle registration plates display black glyphs (alphanumeric characters) on a white background, together with – on the left-hand side of the plate – a blue vertical "EU strip" showing the flag of Europe (or, for older-registered cars, the flag of Bulgaria) and, below it, the country code for Bulgaria: BG. The characters displayed in the main field of the plate are: The format is thus XX NNNN YY, where XX (or X) is the province code, NNNN is the serial number, and
International vehicle registration code on 21 May 1977, in signatory countries it replaces previous road traffic conventions, notably the 1949 Geneva Convention on Road Traffic, in accordance with its Article 48. One of the main benefits of the convention for motorists is the obligation on signatory countries to recognize the legality of vehicles from other signatory countries. When driving in other signatory countries, 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