This section lists the Rootes Private and Confidential Service Bulletins which were issued to service agents to update them with important information. They were to amend the workshop manuals used in maintaining customer's cars and also provided advice on changes to the specifications or accessories. The numbers of the bulletins therefore follow the section numbers of the Rootes workshop manuals. Note this is not the same as the sections in the parts list.
The issuing of bulletins is probably the most important manifestation of the Engineering Change Request process, as you can see the immediate effect upon car production, servicing and ultimately your own car.