[sourdough]

Looking at the pic it appears your fresh water tank fill is the upper connection. Bottom left looks like city water inlet; bottom right is black tank flush. Labels are certainly not intuitive but that appears to be how it' laid out. Someone else may have a different opinion. I believe the lone "attachment" on the side wall in a fresh tank vent/possible overflow. I don't know why that would be in a convenience center but then again I have a hard time understanding a lot of things they do when they build an RV. Others will chime in I'm sure.