Standard Code of locomotive head lamps or discs

Unless otherwise shown in the Sectional Appendix, all engines must carry head lamps or white discs as described in Diagrams A to K below.

Each train will be signalled and take precedence in accordance with the engine head lamps, or discs, except where instructions are issued to the contrary, and Drivers will be responsible for seeing that the proper head code is carried.

Where discs are not provided unlighted lamps are to be carried in the prescribed position in the daytime.

Guards must instruct Drivers to alter their head lamps or discs when any change in the classification of the train is necessary.

When a train is worked by two engines attached in front of the train, the second engine must not carry head lamps or discs.

Classification	Head Code Lamps or discs	Description of train
A		Express passenger train, newspaper train or breakdown van train or snow plough going to clear the line or light engine going to assist disabled train. Officers' Special train not requiring to stop in section.
B		Ordinary passenger train, mixed train, or breakdown van train Not going to clear the line. * Branch passenger train.
C		Parcels, fish, fruit, horse, livestock, meat, milk, pigeon or perishable train composed entirely of vehicles conforming to coaching stock requirements. Express freight, livestock, perishable or ballast train piped fitted throughout with the automatic brake operative on not less than half of the vehicles. Empty coaching stock train (not specially authorised to carry "A" head code).
D		Express freight, livestock, perishable or ballast train partly fitted with the automatic brake operative on not less than one third of the vehicles.
E		Express freight, livestock, perishable or ballast train partly fitted, with not less than four braked vehicles next to the engine and connected by the automatic brake pipe. Express freight, livestock, perishable or ballast train with a limited load of vehicles not fitted with the automatic brake.
F		Express freight, livestock, perishable or ballast train not fitted with the automatic brake.
G		Light engine or light engines coupled. Engine with not more than two brake vans.
H		Through freight or ballast train not running under class C, D, E or F head code.
J		Mineral or empty wagon train.
K		Freight, mineral or ballast train stopping at intermediate stations. * Branch freight train. Freight, ballast or Officers' Special train requiring to stop in section.