Buck... I interpet that the requirement of 551.71 that RV site electrical supply have a 125-volt 20-amp plug addresses a RV site only and a 30-amp 125-volt outlet installed at a single family dwelling for RV power does not require the 20 amp receptacle.
Article 551 part VII Recreational Vechicle Parks
I will make sure that the homeowner does have a 125-volt GFCI protected receptacle nearby for their safety.
Maybe the NFPA needs to address installations such as this one in the 2008 code.
