Go here for "CORRECT" information:
http://www.tirerack.com/tires/tirete....jsp?techid=55
ST-Metric sized special trailer service tires will be branded with their load range (Load Range D or LRD) on their sidewalls and list their appropriate load range letter in their descriptions as ST205/75R15 LRD.
Near the bottom of that page you will find a chart specifically outlining ST tire designations. I'll try to reproduce it here, but the spacing may not come out correctly.
ST-Metric Trailer Service Tires
Load Range Ply Rating Markings Max Load Pressure
B 4 B 35 psi (240 kPa)
C 6 C 50 psi (350 kPa)
D 8 D 65 psi (450 kPa)
E 10 E 80 psi (550 kPa)
The website you listed is an RV dealer's site outlining the data for a specific RV he has for sale... The information he listed is "suspect" at best and an "outright lie" in some areas.... If you notice, he doesn't list the "front tires" on that RV, only the "rear tires" And he has the designation for load range listed as speed range...
Go to an "expert" in tires not an RV dealership ad when you're looking for information on tires.... The link I listed above is from Tire Rack, Inc. a well known and respected tire authority on the internet.
If you have quesitons about what to best install on your RV, you've been given reams of information on this website already. If you can't interpret the data you have available, please contact an expert in tires (a respected tire dealer) in your area... Looking for "conflicting information" on various websites on the internet will only serve to confuse you and make your decision much more difficult... It was my understanding from your previous posts that you were buying Maxxis 8808 tires in the same size as your existing tires (ST205/75R/15 LRC) these are 6 ply radial tires with a standard inflation of 50 PSI. Have you changed your mind? or have you not decided on those tires?
I think you are overanalyzing the data and coming up with conflicting (incorrect) information from suspect internet sites and that you're becomming very confused... Talk to an expert, you'll get much more accurate data and help with your tire choices.