Each volume in the Signal Box Register series includes details of every known signal box within the area of coverage together with line maps, photographs and a selection of thumbnail views of signal box diagrams.
The arrangement of areas of coverage is broadly in line with the British Railways Regional Structure as it stood at nationalisation. However, the London Midland Region is split across three volumes. Some lines appear in more than one volume. The volumes are:
1. Great Western
7. North Eastern + London Midland (Central Lines)
2. London Midland (Midland Lines)
5. London Midland (Western Lines)
8. London Transport
9. Northern Ireland + Republic of Ireland
Within each volume are sections on the RailRef system and the relevant SRS classifications of locking frames and signal box types.
An update service for the DVD edition is available to Members (only).
A corrigenda sheet is available for the first edition of volume 1 (Great Western). A corrigenda and Addenda sheet is available for the other volumes and editions published so far, and this is reissued annually. Both sheets may be downloaded free of charge by clicking on the links.