Years ago I was a truck driver in the Army and gained a decent bit of experience operating a variety of heavy vehicles, from military-specific equipment like HETs and HEMTTs to trucks that have more obvious civilian counterparts such as 800- and 900-series tractor trailers. As it so happens, I was grandfathered (written test and DOT physical only) into a class A CDL that I have never used, and have no real intent to use. Nevertheless, I'm curious: if I were to rent a class A or B vehicle from, say, Ryder Truck, what legal documentation would I require in order to operate it legally? I'm not talking about HAZMAT or tanks or anything like that; just a box truck/trailer. Thanks for any information.