110 Volt AC: Hot, Neutral, Ground
12 Volt DC: Positive, Negative (negative ground to chassis)
110 V neutral is not bonded to ground in RV's at the RV electrical panel.
Here's some info: 120 VAC in your RV
If neutral and ground are bonded and you plug into a reversed polarity outlet then you, someone else, or your pet potentially could become the path to ground.
The two RV's I have now both have a separate 12V buss bar for common 12V negative connections. That buss bar is located near but outside of the panel/converter enclosure.
You might find various color wires used on the 12V side.
Talking to an electrician about this would be a good idea.