The sign you are referring to is called "Special notes on the side stripe indication." This sign indicates that drivers are allowed to drive on the side stripe, which may not be the usual traffic lane.

In Germany, the side stripe (also known as the shoulder or emergency lane) is generally reserved for emergency vehicles. However, this sign signifies that in specific circumstances, like traffic jams or when instructed by police, vehicles may be permitted to use the side stripe to help alleviate congestion.

It's important for drivers to use this option only when safe to do so and to yield to emergency vehicles that may need to use the lane. Always be cautious and aware of your surroundings when considering moving onto the side stripe.

If you have more questions about driving rules or need further clarification, feel free to ask!