The CDs that replace the printed manuals don't have the world most convenient index. These indicies hyprlink directly to the CD in your computer and make navigation a little easier.
While this index is for the 123 chassis CDs, it also seems to work for the 126 chassis CDs as well, presumably because MB uses the same job number and filenames. It's unknown how well it works for other chassis. If it turns out there are significant differences with other models the indicies will be broken out by chassis type.