Thanks to those who did their best to explain UVW. I find it interesting that the spectrum of answers was so varied and of course every person who provided an answer was just as sure their answer was correct and all the others were wrong. I have sent an email to the manufacturer of my trailer to get their answer and will report back what they say on the topic.
The whole reason for the question is that I have some odd looking weights on my trailer. The yellow sticker UVW is 5810. However, the CAT scale weight of the trailer (call it Loaded Vehicle Weight or LVW, including TW) is 8040 with empty water/holding tanks but loaded (actually on) a trip. That means I have added about 2230 pounds of stuff.
I didn't take the TT to the CAT scale the day I bought it and have no intention of taking everything I've added off or out and returning to the CAT scale. So, yellow sticker UVW is all I have to go by. I took delivery of the TT as it was delivered from the factory and there are no dealer installed option on the unit. I still don't really know if UVW includes propane and battery or not as the opinions are about 50/50 on that.
I find it hard to believe I have 2230 pounds of my stuff in the trailer. Just 2 of us with clothes, food, #15 dog and a couple of lawn chairs. Plus a #131 Honda generator w/#18 of gas in it. I carry my tools and bikes in the tow vehicle. I'm just trying to figure things out as I would like to be a little lighter. All of my weights are under specs but I would like a little more margin of error.
I could post the individual GVWR, GAWR, GCWR, tire capacities, etc. I have all the other specifics but don't really want to bore everybody with the details. I have weighed each axle of the tow vehicle, TT and the tongue weight. Each one while hitched and while unhitched. So I'm not lacking for information that can be measured. It's just the manufacturers weight information where I was looking for details and I guess the best place to get that info will be from the manufacturer.