A license group answers one question — how big a vehicle may you drive. Endorsements answer a different one: what may you pull, what may you carry, and whom. Under § 383.93(a)(1), in addition to passing the ordinary knowledge and skills tests, a person who operates or expects to operate the vehicle types the section lists must pass SPECIALIZED tests to obtain each endorsement, and a State may issue an endorsement only to a driver who successfully completes those tests. There is no experience route and no equivalence: the test is the only door.

§ 383.93(b) names five. Double/triple trailers. Passenger vehicles. Tank vehicles. Vehicles used to transport hazardous materials as § 383.5 defines them. And school buses. What each one demands differs, and § 383.93(c) sets the split that decides how much preparation each represents: double/triple trailers, tank vehicle and hazardous materials each require a knowledge test, while passenger and school bus require a knowledge test AND a skills test. The two that put people in the vehicle are the two that make you demonstrate, not merely recite. The panel sets the split out.

One limit belongs here rather than in the chapter on permits. Under § 383.93(a)(2), only three endorsements may appear on a commercial learner’s permit at all: passenger (P), school bus (S) and tank vehicle (N). A learner cannot carry a double/triple or hazardous materials endorsement, however far along the training is. § 383.93(a)(3) then requires States to use the codes listed in § 383.153 when placing endorsements on a permit or a license, which is why the letters on the card mean the same thing in every State — the code, not the wording, is the standard.