The **rear fog light** is not a lighting device on the vehicle. Although it is important for visibility, its main function is to eliminate fog from the rear window, thus improving rearward visibility, but it does not illuminate the surroundings or help others see the vehicle.

On the other hand, the **brake lights** and the **parking lights** are indeed lighting devices:

- The **brake lights** turn on when the driver presses the brake, alerting vehicles behind that the vehicle is slowing down or stopping.

- The **parking lights** are used to indicate the presence of the vehicle when it is parked, especially in low-light conditions, so that other drivers can easily see it.

In summary, the rear fog light does not serve the function of lighting, unlike the brake lights and parking lights, which are indeed part of the vehicle's lighting system.