Final answer:
The rules that apply on a signalled siding are the Siding Control territory rules, which are distinct from the Main track rules and ensure safety and efficiency for trains operating on these sections of the railway.
Step-by-step explanation:
When a student asks about the rules that apply on a signalled siding, they are referring to the regulations that govern train movement in that particular section of a railway. The correct answer to the question What rules apply on a signalled siding? is Siding Control territory rules. These rules are specific to the area of the track designated as a siding, where trains may be stored or allowed to pass each other. Main track rules generally do not apply here unless specified, as the siding is not part of the main track. It's essential to adhere to these rules for safety and efficient railway operations.