Schema-derived ontology reference

This is a draft semantic artefact derived from the PDTF schema, its dictionaries, documents and recorded decisions. Everything here is generated from the committed TTL corpus at source/03-standards/ontology/ and guarded by the doc-drift CI gate. Reproducible generation makes it a canonical reference for that committed corpus; it does not make the draft an approved standard or the SPDTF ontology.

SPDTF reuses this corpus as attributed evidence. Start with why ontologies and the current domain-led method.

This ontology is separate from the PDTF schema. The JSON Schema package, dictionary, glossary and related evidence are its attributed sources; the ontology remains a separately status-labelled draft and is not an endorsed scheme. The Property Pack lineage records what is proven and what still needs a semantic crosswalk.

The combination principle

No single off-the-shelf tool documents the whole ontology — the OWL generators skip SHACL and treat SKOS unevenly, and none render the OPDA-specific layers at all. So this reference is one woven composition of three methods (ADR-0041):

• Tool renderings — the best off-the-shelf tool per layer (pyLODE / WIDOCO for OWL, SHACL Play! for shapes, Ontospy / Skosmos for SKOS), scored in the bake-off.
• Custom opda-gen scripts — the OPDA-specific layers no tool covers: the overlay profiles + GAP register, the round-trip exemplars, and the three-graph separation.
• LLM-authored prose — the conceptual / governance layer a generator cannot emit: why the model is shaped as it is, the decision provenance, and the known-issues register.

Redundancy with neighbouring sections is intended and fine (ADR-0041 rev-3, M1) — this section is designed standalone. For how the model was built see Modelling; for the DAMA four-tier reader presentation see Model.

Live headline counts

Read at build time from the committed TTL corpus — these numbers cannot drift from the model without failing the doc-drift gate.

Profiles are mostly thin by design — they bind Category-G leaves only, and GAP-register the rest (224 bound / 1095 GAPped at session-034). See Known issues for why that is the ratified outcome, not an omission. Downloadable TTL bundles are on Consume the ontology.

Explore the reference

Choose the task that brought you here. Each category page explains its scope and authority boundary before linking to the detailed generated and hand-authored views.