For which scenario is a CALL-ON signal applicable?

A CALL-ON signal is specifically designed for situations where a train must be allowed to proceed under caution, typically after being instructed to stop due to a signal. This type of signal is used to give the train crew permission to move while still requiring them to observe restrictions and be prepared to stop if necessary. In this context, "following manual procedures" often indicates that the operator must be aware of their surroundings and ready to react depending on the track and environmental conditions.

This situation is different from enabling full-speed travel or proceeding without any restrictions, which implies a more unrestricted form of movement that would usually be covered by other signaling protocols. By contrast, the CALL-ON signal requires a careful approach, ensuring the train crew is vigilant and responsive to any potential hazards that may arise. Thus, it serves as an important warning mechanism in train operations, emphasizing safety and adherence to procedures.