2021-04-07: https://github.com/evildmp/diataxis-documentation-framework/... Add license CC-BY-SA 4.0
2021-04-30: https://github.com/divio/diataxis-documentation-framework/co... Copyright change from Danielle Procida to Divio
edit: fixed link
It's already a weakness of this "theory" that it leaves only the reference for documentation that's intended to be complete and correct, while also recommending that the reference be organised as a list of the available operations.
But this divio variant goes so far as to say that, when writing the reference, "don't allow explanations of concepts".
I believe good documentation often needs rigorous definitions of the concepts involved, not just a list of functions or configuration items or whatever.
So either the reference should have space for those, or the explanation should be in a more rigorous style, not a "more relaxed" discussion.