The sign "Prohibition of turning" indicates that vehicles are not allowed to turn in the direction indicated by the sign. In Germany, this sign is typically displayed as a red circle with a horizontal white bar through the center.

This prohibition can apply to left or right turns, depending on the specific orientation of the sign. It is important for drivers to adhere to this rule to ensure safety and maintain traffic flow, especially in busy intersections or areas where turning could create obstructions or hazards.

Always look for additional signs that may provide more context, such as whether the prohibition applies at all times or if there are specific hours when it is enforced. Making illegal turns can result in fines or penalties, so it's crucial to observe and obey these signs while driving.