ROAD VEHICLES ( DISPLAY OF REGISTRATION MARKS) REGULATIONS 2001 REGULATION 8 2) A registration plate must be fixed on an Agricultural machine in a vertical position or, where that is not possible, in a position as close to the vertical as is reasonably practicable - a) on both sides of the vehicle, so that the characters of the mark are easily distinguishable from both sides of the vehicle, or b) on the rear of the vehicle, so the characters of the mark are easily distinguishable from behind the vehicle, or c) where the agricultural machine is towing a trailer or trailers and the plate is not fixed on the sides of the machine, on the trailer or rearmost trailer ( as the case may be) so that the characters of the mark are easily distinguishable from behind the trailer 3) Where the towing vehicle is an agricultural machine, a plate fixed on the trailer may, instead of displaying the registration mark of the towing vehicle, display the mark of any other agricultural machine kept by the keeper of the towing vehicle. REQUIREMENTS FOR REGISTRATION PLATES SCHEDULE 2 PART 3 VEHICLES REGISTERED BEFORE 1ST JANUARY 1973 Either of the following is permitted 1) A plate made of reflex- reflecting material complying with British Standard BS AU 145(45) published on 31 OCTOBER 1967 and which displays black characters on a white background where it is fixed on the front of the vehicle and black characters on a yellow background where it is fixed on the rear of the vehicle. 2) A plate displaying white, silver, or light grey letters and numbers on a black surface having every character indelibly inscribed on the surface or so attached to the surface that it cannot readily be detached from it, which may either - a) be made of cast or pressed metal with raised characters, or b) consist of a plate to which seperate characters are attached, or c) consist of a plastic plate having either reverse engraved characters or characters of a foil type, or d) consist of an unbroken rectangular area on a surface of the vehicle which is either flat or, if there is no flat area where the mark is required to be displayed, an area which is almost flat. (this refers to registration marks painted on the front of tractors below the grille)