The sign you referred to as the "School bus stop" is a traffic sign indicating a designated area where school buses stop to pick up or drop off children. In Germany, this sign is crucial for ensuring the safety of young passengers.

When you see this sign:

1. **Stopping Requirement**: Drivers must stop their vehicles when a school bus is stationary with its flashing lights activated. This means children may be boarding or disembarking, and it's essential to ensure their safety.

2. **Speed Limits**: There may be specific speed limits in place near school bus stops, often reduced to protect children. Always be vigilant and adhere to these limits when driving near schools or designated school bus areas.

3. **Caution**: Even when the sign is not illuminated, remain cautious in these areas as children may still be present.

It's essential to follow these rules to contribute to the safety of children traveling to and from school. If you have any more questions about this or other signs, feel free to ask!