Each vehicle must display two registration plates: one at the front, and one at the rear of the vehicle. The front plate has black characters on a white background, and the rear plate has black characters on a yellow background. The height of the letters and numerals are not less than 8 cm (3.1 in) and not more than 11 cm (4.3 in). The plates should comply with British Standard B.S. 145a, and have permanently marked on the plate the specification number "B.S. AU 145a".Schedule 4 of the Road Traffic (Registration and Licensing of Vehicles) Regulations (Cap. 374E) - td.gov.hkREQUIREMENTS FOR REGISTRATION PLATES - legislation.gov.uk
