...Your drivers license is recognized and accepted by other states and that is where it stops...
I am reading several places that this may not quite be true as it applies to double towing in California, and possibly some eastern states, be it commercial or RV. Many sites insist that you must have a commercial drivers license with doubles endorsement to tow a double trailer setup in California no matter where you come from and what is ok there for this combination.
I am looking for legal clarification not, what you have gotten away with while pulling thru Ca. I am sure lots of us would like to know.