I see some mentioning the GFCI 20A ckt generally found on most pedestals if used in addition to the 30A ckt as being "cheating or using more than one has paid for". My take is that that ckt is included in one's electrical charge and using it in addition to say the main 30A ckt is NOT CHEATING or STEALING. The only way IMO to CHEAT OR STEAL is if one uses a 50A service when one has only paid for a 30A site when the costs are different between 30 and 50A sites and of course say running an additional power cord to another sites pedestal that you have not paid for.
Personally, I always ask for a 50A site and use my dual 30A to 50A dogbone to power my two 30A shore power cords to my trailer which gives me 60A of available power.
Larry