Pedagogy
Notes that TEACH a part of the system from the ground up, in plain words — written so a reader (human or agent) can go from cold to judging real design decisions.
The Pedagogy index gathers the teaching notes. A pedagogy note differs from a reference note in its contract with the reader: reference records how a thing works for someone who already has the map; pedagogy builds the map — ground-up, plain words first, jargon glossed at first use, diagrams that carry meaning, and it earns its keep by ending at a real decision or bug the reader can now judge for themselves.
House rules for writing one: teach one slice, not the world; every concept arrives with the problem that makes it necessary; prefer a true story (a bug, a fork, a review fight) as the finale — teaching without a point is a tour.