This Washington state link:
WA State Licensing (DOL) Official Site: Types of CDLs
seems to provoke more questions than it answers
View attachment 793652
Class A doesn't cover GCWR > 26k if the trailer is 10k or under.
But, "Washington State doesn't recognize class A passenger vehicles", so what's a passenger vehicle? A bus? Is my crew cab with kids in the back seat a passenger vehicle even if it's towing a GVWR 16k trailer with an excavator on it? I'm guessing a truck is not a passenger vehicle; when it's towing the primary function is towing and not hauling passengers.
Class B is for a truck over 26k. Easy enough to understand. But, it makes it look like towing any trailer 10k or under requires a class B??? I have to think that this is for "a truck over 26k towing a trailer under 10k" (if it's over 10k, you're class A).
The (s) in "vehicle(s)" under the class A is for towing two trailers at once (requires a CDL endorsement, same linked page).