What is mandatory for crew members when fouling a track and reporting a passing train?

Crew members must indicate the passing train by its engine number when fouling a track and reporting a passing train. This requirement is crucial for clear communication and safety; providing the engine number allows dispatchers and other crew members to accurately identify the train involved. It helps to ensure that everyone is aware of which specific train is passing, allowing for better coordination and response measures.

By using the engine number, crew members can avoid confusion, particularly in situations where multiple trains may be operating in the vicinity. This clarity is essential for maintaining safe operations and preventing accidents. Accurate reporting also aids in the timeliness of actions taken in response to the situation, fostering a safer railway environment.

The other options generally do not meet the necessary standards for communication safety in this scenario, emphasizing the importance and correctness of reporting using the engine number as mandated.