Propane fittings are none of these, they are similar looking but do not interchange.
I'm not sure who sets the standards, (It appears that ANSI Z21.XX is the standard that covers Sockets and Plugs for LP and Natural Gas, certification to the standard is done by CSA or other organizations) but they are a standard design that if advertised for low pressure propane, will work. They have a thinner wall and larger opening thru them. Always brass.
If you want a real, made to the standards, meets all the specs including markings and such, go with one made by
MB Sturgis or
Marshall Excelsior.
Female couplers will have a miniature ball valve incorporated in them.
Curiously, my trailer had a genuine MB Sturgis coupler on it, and the China made nipple on the hose would not fit. It was two or three thousandths larger than what it should have been and would not go in. I had a China made coupler and replaced the MB Sturgis with it. Here is what I found when I removed the one Bigfoot had installed from the factory. Yes, they used the proper yellow thread tape on the threads.