It appears that ConTeXt is more structured than LaTeX2e in terms of naming scheme, key-value naming, macros, etc. However I haven't seen any guide or so that explains how this structure works.
Where should I look? How do I start learning?
! used in macros mean? E.g.,
_ used in macros mean? (I suppose this is just to add clarity)
What is the meaning of
Where do all of those
\setupfoo come from? I don't see where they are defined.
How are all of those
This is just what came to my mind after reading a few lines of a small .mkiv file. I don't need the answer to all of this, I'm just trying to understand conventions rather than explicit problems. That's just an example of what might come to your mind after reading a little bit about the core of ConTeXt… and I'm not sure the answer to that is easily reachable on the web.
Most important, is there a way to learn that? Is it written somewhere?