Edward t:
Perhaps I was not very clear with my writing.

Of course this particular chapter of the standard applies only to the trucks which have the technical ability to tow a trailers.
This includes of course tractors, but conterbalanced forklifts too.

The standard itself applies to all industrial trucks, but obviously some topics have limited application. In this case, they are the trucks which have a hitch.
In other cases, it's application is limited only to the trucks with the lift chains (chapter 4.6.1) or overhead guard (4.9.1).

Generally, my conclusion is as yours. You simply defined it more precisely.
ISO recognizes the praxis of towing application realized by non-tractors. And, defining the safety requirements, accepts it.
For me, personally, it's a waste of specialized machine, but as my customer stated, for him it's economically reasonable.