These Regulations amend the Road Vehicles (Display of Registration Marks) Regulations 2001. Regulation 3 amends regulation 16, to introduce the legal requirements for the option for an eligible vehicle and trailer, being towed by an eligible vehicle, to display a green coloured plate or other device positioned to the left-hand side of the registration plate, to identify the vehicle as a zero-tailpipe emissions vehicle, with or without an optional emblem and arrangement of letters set out in regulation 16(9) and (10).