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 International vehicle registration code The country in which a motor vehicle's vehicle registration plate was issued may be indicated by an international licence plate country code, formerly known as an International Registration Letter or International Circulation Mark. The sign must be displayed on the rear of the vehicle. The sign may either be placed separately from the registration plate, or be incorporated into the vehicle registration plate. The allocation of codes is maintained by the United Nations Economic Commission for Europe as the "Distinguishing Signs Used on Vehicles in International Traffic" (sometimes abbreviated to DSIT), authorised by the UN's Geneva