CDL?
Commercial driver's license.
Commercial Drivers License, According to the rating on the license you can drive commercial vehicles. Mine is Class A with passenger and Motorcycle endorsement.
Means I can drive Tractor-Trailers Charter busses or anything in between. They have one other endorsement and that is fior Hazmat. I had no desire to get that one.It is needed to haul chemicals. gasoline or explosive gases.
Commercial Licenses require a medical certificate to be in your possession at all times while driving, and you must be given a physical every two years. Its every year for school bus operators.
I dont know if these rules apply to the new laws governing Mexican drivers or not. Would be interesting to find out.