I personally like the website,
www.rgsonline.co.uk, with its section on rulebook modules. I can see why it would be confusing though to the uninitiated with different modules for lines signalled by ERTMS not to mention the sections on electrified lines, as has already been suggested but I would have thought that anyone who is train driver material would have the gumption to determine what is applicable to them.
The different modules and sections are labelled quite clearly with the roles for whom the information is intended, be it a driver, guard, shunter, signaller, etc.