Modelling
The technical semantic-modelling workstream. PDTF today is JSON Schema; the work is to elevate it to a full linked-data stack — bounded contexts → controlled vocabulary → SKOS taxonomy → OWL ontology → SHACL validation → JSON-LD mappings — so that property data is verifiably interoperable across the UK industry.
Foundations
The architectural decisions and domain partitioning that shape every other modelling artefact.
Standards stack
PDTF schemas, OpenAPI, repos. The five-layer technical stack we're modelling on top of.
Bounded contexts (DDD)
Six primary industry contexts + five supporting contexts. PDTF is the Published Language between them.
PDTF overlays
Full catalogue of all 18 main + 16 extension overlays — definition, merge mechanics, and how each maps to a bounded context.
Vocabulary & dictionary
The shared terminology that everything else maps to.
Data dictionary
All 8,458 schema property entries, browseable inline. Headline numbers, audit, schema inventory, build pipeline and sources alongside.
Business glossary
All 554 SKOS concepts (54 curated OPDA terms + 500 schema-derived), browseable inline. Provenance, kind breakdown, and editorial roadmap alongside.
Concept taxonomy (SKOS)
Hierarchical organisation of PDTF concepts. 9 top-level branches, deepening per overlay.
Formal semantic layer
The machine-readable specification of what the data means — not just what shape it has.
Ontology (OWL)
Classes and properties for Transaction, Property, Participant, Claim, Document, Form, Search. Reuses W3C VC, Schema.org, FOAF/ORG, GeoSPARQL.
SHACL shapes
Validation rules in RDF land. Mostly translatable from JSON Schema; hand-authored for cross-property business rules.
JSON-LD mappings
Per-overlay @context files that bridge JSON property names to ontology terms. BASPI v5 first.
Status at a glance
| Artefact | Status | Where |
|---|---|---|
| Standards stack survey | ✅ Built | 06-standards-stack.html |
| Bounded-context model | ✅ Built | 12-bounded-contexts.html |
| PDTF overlays catalogue | ✅ Built | 16-overlays.html |
| Data dictionary | ✅ Built (auto-generated + interactive) | 13-data-dictionary.html |
| Business glossary | ✅ Built (54 terms + 554 SKOS concepts, interactive) | 14-business-glossary.html |
| Concept taxonomy (SKOS) | ⏳ Stub — top-level only | 30-concept-taxonomy.html |
| Ontology (OWL) | ⏳ Stub — class list only | 31-ontology.html |
| SHACL shapes | ⏳ Stub — pipeline designed | 32-shacl-shapes.html |
| JSON-LD mappings | ⏳ Stub — BASPI v5 to be first | 33-jsonld-mappings.html |