ADAS systems (Advanced Driver Assistance Systems) are technologies designed to enhance safety and driving. However, not all of these systems are allowed during practical driving tests.

- **TSR (Traffic Sign Recognition)**: This system recognizes traffic signs and displays them to the driver. It is not allowed in practical tests because it could give the examinee an advantage by reminding them of traffic signs, which is a skill evaluated during the test.

- **Hill Holder**: This system helps prevent the vehicle from rolling backward when starting on a slope. There is no mention of any restriction on its use in practical tests, so it is allowed.

- **AEB (Autonomous Emergency Braking)**: This system automatically brakes the vehicle if it detects an imminent collision. Like the Hill Holder, it is not mentioned as being prohibited in practical tests, so it is also allowed.

Therefore, the **TSR** is the system that is not allowed in practical tests.