I'm not telling anyone that their research is wrong. All of the above may all be 100% valid without conflicting with my experience in Ontario, Canada.
Examples of differences include:
1. Here a class B applies to school buses which are considered just a notch below an A (which permits you to drive pretty much anything) but above public transit or inter-city buses (class C) and straight trucks over 11000kg (class D, but no trailers over 4600 kg which require an A class either with or without R restriction). Classes are clearly not consistent between jurisdictions, other areas may use numbers or letter for classes, endorsements and restrictions and the way they are grouped also seems to vary.
2. Here an airbrake endorsement (code Z) is also required for air boosted hydraulic brakes such as on the military M135 or M211 series. I get a headache trying to understand just the rules here, without considering other areas. As an example of a possible (but possibly a bit unusual) combination, I currently hold a class BM license with Z endorsement and X restriction (glasses required). An example of what I don't understand is whether I can keep my current BM with Z (which includes airbrake trailers) but add an A(R) and then tow an airbrake trailer. My Z endorsement should permit it but the R on an A normally wouldn't. The point of the A(R) is to be able to tow a trailer of over 4600 kg (usually electric brake) behind a pickup (by itself, the A(R) would prohibit air brakes and multiple trailers). Either I'm dumb or the rules are complex... I will need to find a knowledgeable commercial enforcement or licensing source to clarify this, probably smarter if I were to study the Highway Traffic Act and/or the Regulations related to it..... and then discuss.
3. Here I'm required to pass medicals to keep a D or higher license but the license itself is considered proof of the medical (no separate card here) - the frequency of exams depends on my age.
There's nothing to stop you from having a G (cars and light trucks) license with Z endorsement, I used to have this for my M135CDN toy/restoration.
A link to a document I found summarizing Canadian drivers' licenses is at https://www.fmcsa.dot.gov/sites/fmcsa.dot.gov/files/docs/Canadian%20Driver%27s%20Licence%20Reference%20Guide%20Revised%202015.pdf
There is definitely supposed to be some sort of reciprocity - if I'm in another jurisdiction operating in a way contrary to their rules but in a way that would be legal in my home jurisdiction I should be accepted - but I don't really want to test this. I try to operate in a "reasonable" way at all times to avoid drawing attention in the first place.
I hope I haven't said anything incorrect here, or added to anyone's confusion.
Please do your own research to determine the rules both locally and wider area in your place of driving (I don't expect enforcement will listen if you say "I was told..." or "I heard").
