Numerical vehicle index - vehicles listed numerically for easy identification of type
TOPS codes - lists all the codes that were originally allocated to unpowered vehicles and later dropped. Also the National Traction Plan details for 1974.
Diagrams - each vehicle was allocated a diagram number to identify its layout
Departmental vehicles - those that saw further use in areas such as research, sandite or route learning.
Depot/Repair Codes - Demystifing some of the data on the end of vehicles.
Set Numbers - some examples from through the years.