Giving a holding an identity
Accession-level documentation means each holding is addressed individually: it has a stable identifier, and everything known about it hangs off that identifier rather than off somebody’s memory of which shelf it sits on.
It sounds like bookkeeping. It is the difference between a collection you can query and a collection you can only inventory.
Structure is what lets a resource answer a question nobody thought to ask when it was assembled.
Layers, added over time
Provenance arrives first, because it arrives with the material. Observation accumulates each season. Characterization arrives later and unevenly, as it becomes possible and appropriate.
None of those layers has to be complete for the structure to be worth having. They have to be attached to the same identifier.
