The abc.set file should look like this and it will be opened at the Positioning tab.
Selecting the tabs for the Layer Visibility, Ordering, Rendering and Fonts opens those sections of the settings.
It is the Positioning which controls the sizing of the CAD image onto a specific page size.
The Layer Visibility controls what layers will be on or off, Ordering controls what ordering method will be used, Rendering controls what renderstyles are assigned and Fonts controls what font names are assigned to the CAD styles names.
Next let's have a look at the abc.rsl (renderstyles) file before we start to make some changes.