Kayteg1, it appears you did not look at the links I provided.
I am confused by "... pictures posted on the net by rv.net members." I don't see how it is relevant to this thread.
"They are known to stir the pots and post misleading information all the time." Your statement ; "Anything that can and needs to be removed for fill is a cylinder.", is untrue. Portable tanks, known as bottles or cylinders are used as a fuel source for gas grills as well as forklifts. The second link, in my first post, was to show that the tanks used by most TCs are called Tanks by the stores that sell them. I will leave it to you to correct them.