Singapore legislation
Regulation 21
of Road Traffic (Motor Vehicles, Registration and Licensing) Rules
Regulation 21
Illumination of identification mark
Subregulation 1
Whenever a motor vehicle is on a road between sunset and sunrise, the identification mark exhibited at the back of the motor vehicle or at the rearmost vehicle drawn by the motor vehicle shall be adequately illuminated as to render easily distinguishable every letter and figure of the identification mark.
Subregulation 2
It shall not be necessary for a motor vehicle to comply with paragraph (1) while it is parked on an adequately lighted road.