Made as simple as possible, but not simpler.
There are a number of reasons to punt on power in a design, to go with a worse-is-better style such that you express the design in the least powerful way.
The materials paradigm1 may be represented in the form of a tetrahedron2, illustrating a set of material concerns and how they are interrelated.
A sequence diagram can serve as a fat-marker sketch of a happy-path checklist for a spike.
This is a brief note on my perception of the ISO 11179 Metadata Registry (MDR) standard, including my perception of its relation to W3C Semantic Web standards.