I find that it helps to describe the J or APL code as if you are writing a paper about it for the expert. For example, see the essays in the J wiki. If carried to the extreme, it becomes the Literate Programming<https://en.wikipedia.org/wiki/Literate_programming>of Knuth.
In such writing it is unnecessary to describe the working of primitives because they can be looked up in the dictionary or reference manual. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
