What does a green flag being slowly waved below the waist mean?

A green flag being slowly waved below the waist signifies that the train driver or operator must proceed with caution. This signal is part of the safeworking practices designed to ensure safety on the rail network. When the green flag is used in this manner, it indicates that while it is safe to move forward, there may be potential hazards or conditions ahead that require the operator to remain alert and proceed at a controlled speed.

Understanding this signal helps prevent accidents and ensures that operators are aware of their surroundings, thereby maintaining a high standard of safety within the rail operations. The specific manner of waving the flag—slowly and below the waist—serves as a visual cue to be extra vigilant, as opposed to other signals that might convey more definitive instructions.