The **high beam headlights** or **main beam headlights** are designed to improve visibility in low-light conditions, such as on roads outside towns or cities at night. However, their use is **prohibited** in certain situations to avoid **dazzling other road users**.

- **Dazzling** means that the intense light can temporarily blind other drivers, increasing the risk of accidents. Therefore, it is crucial not to use these lights when there are other vehicles nearby that could be affected.

- High beam headlights should be used mainly on **poorly lit roads** and when there are no other vehicles nearby. If there are other drivers, they should be turned off or alternated with low beam headlights to avoid dazzling.

- Additionally, within **towns and cities**, and when the vehicle is **stationary**, these lights should not be used, as urban lighting is usually sufficient and the risk of dazzling others is higher.


Therefore, the correct answer is that it is not allowed to turn on the high beam headlights when other users could be dazzled.