This module reads like a factory service manual. A typical entry for "Timing Belt Replacement - 2.0 HDi" includes:
Historically, Citroën's technical data was distributed on physical paper manuals, which eventually evolved into multi-disc DVD sets (commonly referred to as "Citroën Service Box SEDRE" for the wiring diagrams and document viewer). These offline DVD versions were highly coveted by independent mechanics and DIY hobbyists because they allowed full, local access to the automaker's database. citroen service box
You need both for serious repair. You need alone for ordering parts and general maintenance. This module reads like a factory service manual