It is **mandatory** to keep the **rear license plate** illuminated at night on all types of roads. This is because, at night, it is necessary to turn on the vehicle's lights on any road, whether inside or outside towns and cities. The lights allow other drivers to clearly see the license plate, which is essential for vehicle identification and road safety. Additionally, all cars must have two license plates, one at the front and one at the rear, and these must be visible at all times, especially in low-light conditions. Therefore, keeping the rear plate illuminated is a safety measure that applies on all roads.