🚀 go-pugleaf

 FM refers to these magnificent structured manuals, but no specifics on how to put them together.    

Actually it does. The "how" is in the user guide, in the form showing you how to create different types of numbered paragraph situations, for example. 

It's up to the user to do the design, other than what one can find in downloadable templates (at Adobe, for instance), and come up with a workable set of tags, variables, and so on. 

In situations such as those you mentioned (ICAO, IAP, FCOM), a Framer would,  assuming you wanted to mimic the style, work up a set of tags and a layout to do so. 

I would expect to find that if you hunted around in these organizations, you would find some templates that others have done. 

Diving into Frame as a new user who needs complex numbering is not the easiest place to start, but a consultant could certainly help you out.