Thanks for that posting this link. It looks like pretty good information.
However it does show why I have objections to the use of the term "ground".
In the discussion about AC 120/240 the term "ground" means just that, the earth. The green wire is connected to earth at some point in the shore power distribution system, usually at the power distribution box.
In the discussion about the 12 Volt DC the term "ground" means negative
battery. If the RV is NOT plugged into shore power negative
battery is NOT connected to the earth. In some cases but not all, if RV is plugged into shore power the negative
battery terminal might be connected to earth through the converter.
As you can see it gets rather confusing.
Better terms. AC green wire = safety ground.
DC negative terminal = (-) or negative