Mapping is evidence, not architecture

Keep it separate so it cannot deform the material.

A mapping document demonstrates that every requirement is addressed and where. Held as a separate artefact it does that job perfectly well and constrains nothing about how the material is organised.

Used as the structure of the resource it deforms everything: the ordering, the headings, the language and the length of each section, which ends up proportionate to the number of criteria rather than to the difficulty of the content.

The separation also makes maintenance easier. When a unit is superseded, the mapping is what has to be reworked, and a resource whose structure is the mapping has to be rebuilt rather than revised.

The mapping should point to specific locations rather than to sections, since a reference to a whole chapter demonstrates very little and is the form most likely to be challenged.

Keeping it current is the discipline. A mapping produced once and never revised while the content evolved is worse than none, because it asserts a coverage that no longer holds.

The other mapping discipline worth adopting is to record the reasoning for judgement calls. Where a criterion is addressed indirectly, or through a combination of activities, a line explaining why that is sufficient turns a disputable mapping entry into a defended one.