Property Descriptive Attributes

Context and Problem Statement

The descriptive layer is where PDTF v3 volume lives: of 1,556 unique leaves in pdtf-transaction.json (935 annotated), the great majority describe a property (built form, condition, valuation, EPC/energy, utilities, searches, encumbrances, completion). All hang off a deeply nested propertyPack mega-tree, and the same descriptive families recur across every form overlay (baspi5 318, rds 196, piq 184, ta6 178, nts2 160, lpe1 136, …).

Two defects bite. First, attachment: in the schema these facts dangle off propertyPack with no first-class subject — the ontology has no Property class to attach them to (ODR-0005 defect; Cagle Q3: “that nesting is form ergonomics, not ontology — flatten it”). Second, cross-context reconciliation: spanning leaves recur across overlays — propertyPack ×18, energyEfficiency/heating/typeOfConstruction/listingAndConservation ×9, mainsWater/drainage/electricity ×9–10 — and must reconcile to one ontology property, not mint per-form synonyms.

Council Session 001 (Q3) resolved to partition by ontological concern. This ODR is the Property descriptive attributes module under that partition — a Phase-1 module gated by ODR-0005’s identity crux, which MAY later split into sub-modules (built-form / energy / searches / encumbrances) once volume is understood.

Considered Options

• Option A (chosen) — Declare-once-reconcile-overlays. Flatten the propertyPack tree; declare each descriptive property once as an opda: datatype property on the Property/Title class, sourced from the canonical data-dictionary leaf with dct:source + rdfs:comment; reconcile spanning leaves so all overlay occurrences map to that single property; push per-form required/enum variation onto the SHACL overlay profiles (ODR-0010).
• Option B — Mirror the JSON tree (per-form duplicate properties). Rejected: reproduces the propertyPack form-ergonomics nesting as ontology and fractures spanning concepts into per-form synonyms — the exact defect Q3 rejected.

Decision Outcome

Chosen option: “Declare-once-reconcile-overlays”, because it is the only option that attaches descriptive facts to real classes, collapses each spanning leaf to one term, and keeps per-form variation in the profile layer where Q3 and Q5 placed it.

Adopt Declare-once-reconcile-overlays: flatten the propertyPack tree; declare each descriptive property once as an opda: datatype property on the Property/Title class, sourced from the canonical data-dictionary leaf with dct:source + rdfs:comment; reconcile spanning leaves so all overlay occurrences map to that single property; push per-form required/enum variation onto the SHACL overlay profiles (ODR-0010).

Consequences

• Descriptive facts attach to opda:Property/legal-estate classes from ODR-0005; the propertyPack-blank-node defect is eliminated.
• Each spanning leaf collapses to a single ontology property; the ontology gets one term per concept instead of per-form synonyms.
• Every property carries dct:source + rdfs:comment from the dictionary, supporting the BASPI round-trip (loaded profile validates data and regenerates the form).
• The mechanical leaf-to-property mapping is generated from the dictionary; scarce deliberation is reserved for ambiguous reconciliations.
• Reconciling ~935 annotated base leaves (plus overlay-specific leaves) is high-volume work; spanning-leaf detection is now mechanical (SHACL shape-target convergence per Q1a) — adjudication fires only on consumer-query trigger, recorded in the reconciliation register.
• Module gates ✅ CLEARED — S005 3-class ratified; S003b namespace ratified; full upstream TBox (S006/S007/S009/S010/S011/S012/S013/S015) ratified.
• Per-form required/enum variation MUST be authored as SHACL profile shapes (ODR-0010) per Q7a three boundary clauses; descriptive enumerations follow Q5a binding table — §8a-named schemes as SKOS per ODR-0011; non-§8a one-shot enums as xsd:string + sh:in.
• The mechanical 935-leaf walk now begins as implementation work: generator (ADR-0007) emits per-leaf binding table + class promotions per Q4a + reconciliation register per Q1a.
• ODR-0008 is the seventh kind: pattern ODR to discharge under A9 — methodology pressure-test passes 7-of-7 clean.
• Implementation depends on ADR-0007 generator + foundation.ttl emission; subsequent BASPI5 round-trip MVP gate (per ODR-0010 §Q7) exercises ODR-0008’s mapping discipline against real overlay data.

More Information

• Target versions: RDF 1.2 and SHACL 1.2, per the Core-tier pin in ODR-0002.
• Vocabularies: Core (OWL/RDFS/XSD); SHACL for numeric ranges and format patterns (→ ODR-0013); SKOS for the descriptive enumerations (→ ODR-0011); DASH for form-rendering UI (→ ODR-0013); PROV-O for authority-retrieval provenance (EPC Register, HMLR, search providers → ODR-0009).
• Out of scope (deferred per ODR-0002): QUDT for units (kWh, m², W·m⁻²·K⁻¹) — carry xsd:decimal + SKOS-typed units; GeoSPARQL geometry (title plans, search polygons, titleExtents/chargeExtent stringified GeoJSON) — deferred.
• Data dictionary: source/00-deliverables/semantic-models/data-dictionary.md — pdtf-transaction.json base (1,556 unique leaves, 935 annotated) plus per-form overlays (baspi5 318, rds 196, piq 184, ta6 178, nts2 160, lpe1 136, …). The cross-context table is the authority for which leaves span overlays.
• Open questions: whether to split into sub-module ODRs (built-form / energy / searches / encumbrances) once volume is understood — deferred to drafting; the defect/condition taxonomy (RICS classification) and EWS1 / Building Safety Act modelling — UK-specific, deferred to a future council when the PDTF schema adds the structure (greenfield; no WG).
• Deliverables: property-attributes.ttl (likely multiple files under one module namespace); the descriptive SKOS schemes (→ ODR-0011); authority-provenance patterns (→ ODR-0009); the generated leaf → datatype-property mapping with dct:source/rdfs:comment from the data dictionary.
• Related: anchor ODR-0003; foundation ODR-0004; gating crux ODR-0005; agents & roles ODR-0006; transactions & lifecycle ODR-0007; provenance ODR-0009; overlay profiles ODR-0010; enumerations ODR-0011; data-governance ODR-0012; validation ODR-0013; address & geography ODR-0015; SHACL-AF pattern ODR-0017; DPV co-annotation pattern ODR-0018.
• Three-rule interface contract (Scope-Check 1 Q6 / Cagle): ODR-0008 §Operational specifications Q7a cross-cite ODR-0010 + ODR-0013 on (i) sh:in semantics merged at build-time applied to closed schemes; (ii) sh:Violation floor; (iii) no-identity-override gate.
• Cross-corpus ADR dependency: ADR-0007 — Ontology generator specification — implementation of ODR-0008 §Operational specifications depends on the generator’s deterministic emission discipline.
• Council: session-001 Q3 (partition by concern; flatten propertyPack); session-008 Full Council ratification (Allemang Queen; Cagle DA — 6 WITHDRAWN/CONCEDED + 1 HELD + 1 VIGILANCE; ten voices across five teammates). Status proposed → accepted. Seventh kind: pattern ODR to discharge under A9 — methodology 7-of-7 clean.
• Implementation-planning follow-on: session-021 — Bounded-Context Implementation Plan (2026-05-30) found the mechanical 935-leaf walk ready for execution now (~90 % generator-mechanical from the data dictionary; xsd:string-default range, flat per §Q6a, Q4a class-promotion pass), reclassifying it from ADR-0005 §G11’s “demand-deferred” remainder to scheduled mechanical emission (proposed ADR-0028). The same-day convention review session-022 corrected the home/context layer: the walk emits rdfs:isDefinedBy → owning module (concern) + the already-present dct:source; opda:definedInContext is retired and per-leaf opda:requires is dropped as redundant (shapes enumerate required terms). The 935-leaf walk itself is unaffected. Decided on directing authority (greenfield — no WG gate; ADR-0006).

Rules

Attachment — Descriptive properties attach to opda:Property and the legal-estate classes from ODR-0005 (and to intermediate built-form classes such as Building/Room where the fact is about a sub-part). Never to a propertyPack blank node.

Data dictionary as the leaf inventory — The descriptive datatype properties are enumerated from the data dictionary. Indicative families and source leaves:

• Built form — buildInformation, typeOfConstruction/constructionType, builtForm (Detached | Semi-detached | Mid-terrace | End-terrace | Other), yearOfBuild, numberOfFloors, internalArea/area/units, bedrooms/bathrooms/receptions, residentialPropertyFeatures, rooms/roomDimensions.
• Condition — surveys, subsidenceOrStructuralFault, dampProofingTreatment, buildingSafety/buildingSafetyAct, dangerousCladdingOrDefects, japaneseKnotweed.
• Valuation & price — valuations/value, price/listPrice/priceQualifier, propertyPricing/estimatedPrice/rentalEstimate/yield, valuationComparisonData.
• Energy / EPC — energyEfficiency, currentEnergyRating (EPC band A–G), energy/energyRisk, solarPanels, greenDealLoan.
• Utilities & connectivity — heating/heatingType/centralHeatingFuelType, electricity/mainsElectricity, water/mainsWater/waterAndDrainage/drainage, connectivity/broadband/mobilePhone/typeOfConnection, meter leaves (mpan/mprn/electricityMeter/gasMeter).
• Local context (searches) — localSearches/localAuthoritySearches (CON29R), localLandCharges (LLC1), environmentalIssues, floodRisk/flooding, radon/radonRisk, coalMining, localAuthority, nearbyFacilities/schools/transport/healthCare, planning/planningApplication.
• Encumbrances — councilTax/councilTaxBand, groundRent/serviceCharge, buildingsInsurance/insurance, guaranteesWarrantiesAndIndemnityInsurances, rightsAndInformalArrangements/publicRightOfWay, occupiers/lettingInformation, listingAndConservation/isListed.
• Completion & moving — completionAndMoving, fixturesAndFittings/itemsToInclude/itemsToRemove, moveRestrictionDates, confirmationOfAccuracyByOwners.

Sourcing convention — Each descriptive opda: datatype property is sourced from a data-dictionary leaf, carries dct:source to its canonical schema leaf path (the form-question IRI of Q5’s mapping rule) and rdfs:comment from the dictionary’s description text, per the convention defined in ODR-0004.

Cross-context reconciliation — Spanning leaves the data dictionary flags (propertyPack ×18, energyEfficiency ×9, heating ×9, typeOfConstruction ×9, listingAndConservation ×9, mainsWater/drainage/electricity ×9–10) each reconcile to one ontology property. The differing per-overlay dct:source references attach to the single property; per-form required/enum variation is expressed as SHACL property shapes in the overlay profiles (ODR-0010), not as duplicate datatype properties.

Generated, then deliberated — The mechanical leaf → datatype-property mapping is generated from the data dictionary (Allemang’s generator-first rule, Q1). Deliberation is reserved for genuinely ambiguous reconciliations and for which object-typed leaves become intermediate classes (Building, Room, Survey, Search) versus structured datatypes.

Enforcement — SHACL shapes (ODR-0013) constrain numeric descriptive properties to plausible ranges and string-formatted ones to their patterns; the overlay profiles (ODR-0010) carry per-form sh:minCount/sh:in variation for reconciled spanning properties. Cross-context reconciliation is verified by checking that each data-dictionary spanning leaf maps to exactly one opda: property with all overlay occurrences resolving to it. The module is validated against the descriptive facets of the diagnostic exemplars (ODR-0005): the same property described through two different overlays must populate the same ontology properties.

Gate — ✅ CLEARED. ODR-0005’s 3-class identity-criterion gate ratified at S005; descriptive properties attach to opda:Property, opda:LegalEstate, opda:RegisteredTitle (and the named sub-Kinds promoted per Operational specifications §Q4 below). Namespace block cleared via S003b + ADR-0006.

Delegated — Descriptive enumerations (built-form, property-type, units, EPC band, council-tax band, tenancy type) are SKOS concept schemes owned by ODR-0011, not resolved here.

Operational specifications (added by Session 008)

Session 008 (Full Council; Queen Allemang; DA Cagle — 6 of 7 questions WITHDRAWN/CONCEDED + 1 HELD-AS-LIVE + 1 PRIMARY VIGILANCE) operationalised the discipline through seven ## Operational specifications subsections. Original ## Rules above stand; subsections below add the build-time and CI-enforced disciplines.

Q1a — Spanning-leaf detection (no arithmetic threshold)

Mechanical-default + SHACL shape-target detection + consumer-query reconciliation trigger + reconciliation register + Pandit’s PII discovery hook. Every annotated leaf emits one opda: datatype property; spanning leaves are detected by SHACL ?shape sh:targetClass opda:Property ; sh:path ?p grouping (Knublauch); deliberation fires on consumer-query trigger; outcomes recorded in a per-leaf reconciliation register; new spanning-leaf candidates fire ODR-0017 SHACL-AF rule for DPV co-annotation per ODR-0018 §3a.

Reconciliation register

The per-leaf reconciliation register. Each row records, for one leaf: its current G11 home (per ADR-0005 §G11), the recommended disposition — (a) G11 flat emission STANDS (the flat datatype property on opda:Property/opda:LegalEstate is the correct home per §Q5a/§Q6a; curation = confirm rdfs:domain + add the dct:source schema-leaf-path (G2) + bind a SKOS range where §Q5a indicates a scheme) or (b) RE-HOME (the leaf belongs on a descriptive class or under the ODR-0023 R2 axis split — quality / mode / legal-estate), a one-line rationale, and a WG-decision marker. Dispositions are engineering recommendations, not decisions (per ADR-0005 §G1: engineering does not silently reconcile ratified-rules disagreements); the WG (Modelling Sub-Committee) ratifies each. The riskIndicator re-home is the first entry and the worked template; the six rows below are the ADR-0031 work-item-1 G11∩candidate-G overlap, applied 2026-05-31 during the curated Category-G walk (each leaf’s dct:source tightened to its G2 schema-leaf-path and its SKOS range confirmed in opda-property.ttl). The register stands as the reconciliation record of those dispositions.

Q2a — Sub-module spawn-triggers (monolithic-with-named-triggers)

ODR-0008 stays monolithic. Spawn-rule fires on EITHER (a) UFO meta-category crystallisation — when ≥1 sub-module’s leaf-set populates such that Quality / Mode / Substance-Kind-label distinctions are operationally load-bearing, spawn ODR-0008a/b/c by UFO axis with named stewards (Allemang on property-qualities; Guizzardi/Pandit on property-modes; Kendall on legal-estate-attributes); OR (b) authority-retrieved-artefact provenance loss — when Survey/EPC/Search/Title-Plan cannot be flat datatype bags without losing prov:wasGeneratedBy, spawn ODR-0008d “Authority-Retrieved Artefacts” with implements: [ODR-0007, ODR-0017]. Kendall’s four-way alternative held-as-live (18 months or encumbrance-cardinality trigger). (Spawned 2026-05-30 — ODR-0008d, session-024; fired by ODR-0022 Category E. The four-way resolved 7–1 to a RiskAssessment UFO Information Object + a 12-member opda:PerilScheme, with the five §Q4a classes retro-corrected Substance-Kind → Information Object; Cagle DA held-as-live for reuse-opda:Search.) (Arm (a) TESTED 2026-05-31 — session-029, Full panel: judged NOT load-bearing (0–6–0) → ODR-0008a/b/c NOT spawned; ODR-0008 stays monolithic. The curated G walk typed leaves by bearer Kind (rdfs:domain), not UFO meta-category — the presupposed UFO-typed partition was never built — and priceQualifier (straddles Mode/Quality) + ownershipType (quality-by-type, legal-estate-by-bearer) fail OntoClean disjointness/identity for a module boundary (Guarino). legal-estate-attributes (ODR-0008c) is removed from this arm — it reduces to rdfs:domain opda:LegalEstate (= Kendall’s four-way attachment-class split, re-routed to its 18-month/encumbrance-cardinality trigger), not the UFO axis. a/b deferred on a sharpened conjunctive trigger: (i) a committed gUFO rdf:type typing pass over the Property leaf-set with straddlers/re-sorters adjudicated to one cell AND (ii) a named consumer query or SHACL validator whose answer/report changes when the typing is removed. The UFO distinction stays valid as a typing (Guizzardi/Guarino) — preserved via a deferred gated gUFO annotation pass, not a namespace.)

Q3a — Citation grain (per-property + per-overlay array)

Per-property dct:source per ODR-0004 §7a with version-pinned URL. For spanning leaves, an array of dct:source triples (one per overlay leaf-path) — lossless audit in both directions. DPV co-annotations carry parallel per-property dct:source to regulator text per ODR-0018 §6. Round-trip equivalence SPARQL test verifies the per-property + per-overlay array recovers the data-dictionary cross-context table. Cagle’s section-level opt-in HELD-AS-LIVE for 18-month review.

Q4a — Three-criterion class-promotion test

A leaf or leaf-cluster promotes to a Class iff ANY of: (a) authority-retrieved provenance (prov:wasGeneratedBy chain to regulator-issued or professional-issued activity); OR (b) distinct lifecycle (issued / superseded / re-issued / withdrawn); OR (c) distinct PII regime per ODR-0018. Definite Class promotions: opda:Survey, opda:EPCCertificate, opda:Search, opda:Valuation, opda:Comparable — each retrofitting implements: [ODR-0007, ODR-0017, ODR-0018]. Conditional Class promotions held-as-live (Davis dissent): opda:Building, opda:Room — convene on first named BASPI5 round-trip query exercising sub-Property reasoning. (ADJUDICATED 2026-05-31 — session-030, Full panel (8): NEITHER promoted — opda:Room 8–0 (no data-realisable IC; roomName non-rigid, no positional token), opda:Building 7–1 (genuine +O IC via ODR-0005 §3a-4 Replacement, but latent/unexercised). The length/width/roomName repeating group is modelled as an anonymous by-value opda:RoomDimension structure on opda:Property — NOT a class (ODR-0024 R10). Promotion re-opens only on an identity fact — a Building instance / a stable room token — not a calendar gate.)

Q5a — Datatype vs SKOS per-leaf binding table

ODR-0011 §8a-named schemes become SKOS concept schemes; non-§8a one-shot enums stay xsd:string + sh:in. Burden of SKOS promotion on the proposer per leaf. The classify-vs-subclass call is governed by the ODR-0011 §8a load-bearing cascade (Council session-036): default to a coded facet + sh:in; promote a label to an OWL sub-class only on a distinct identity criterion (+I). The tenureKind “sub-Kind via skos:exactMatch” row below is realised coded-only — tenureKind is +R∧−I, so NO Freehold/Leasehold/Commonhold sub-class is minted (session-036 keystone correction). Initial binding table:

Kendall’s “SKOS for all category-likes” HELD-AS-LIVE with 18-month re-open trigger on downstream consumer demand.

Q6a — Hierarchy admission discipline (flat-default + reasoner-independence)

Flat default — every descriptive datatype property is owl:DatatypeProperty with no rdfs:subPropertyOf in initial emission. Hierarchy admission requires (i) named consumer query asking for parent-level entailment with query text reviewable; (ii) reasoner-independence test (UNION-over-children must equal entailed-parent answer-set; if they differ, the hierarchy is decorative under entailment-off SPARQL endpoints). SKOS broader/narrower for value-spaces (per ODR-0011 §Rules) — distinguished from predicate hierarchies. Kendall’s opda:hasUtilityConnection parent HELD-AS-LIVE — re-open at first SHACL profile forced to UNION across utility-children.

Q7a — Overlay-form variation: three boundary clauses + three CI tests

Three explicit boundary clauses for the handoff to ODR-0010:

1. Base-cardinality clause: base TBox 0..* for every descriptive property; per-form sh:minCount lives in ODR-0010 profile shapes.
2. Enum union clause: spanning leaves with differing per-overlay enum sets — base SKOS scheme carries the union of all overlay members; per-form sh:in restriction in ODR-0010 (per Cagle’s Scope-Check 1 Q6 three-rule interface contract; sh:in semantics merged at build-time).
3. Advisory annotations clause: form-ergonomic guidance lives in opda-annotations.ttl (NOT base TBox or profile shapes — re-instantiates S001 Q5 + ODR-0004 §3a).

Three SHACL CI tests (added to ODR-0004 §3a five-part CI suite):

1. ASK { ?p a opda:DescriptiveProperty . ?p sh:minCount ?n . FILTER (?n > 0) } returns FALSE in base opda-shapes.ttl.
2. For each spanning leaf, the union of per-profile sh:in members equals the SKOS scheme’s skos:Concept set.
3. ASK { GRAPH opda:annotations { ?s a sh:NodeShape } } returns FALSE.

Three-rule interface contract cross-cite to ODR-0010 + ODR-0013 is in §References.

Attachment model: descriptive properties on real classes

Descriptive properties attach to opda:Property and legal-estate classes — never to the propertyPack blank node — with authority-retrieved leaves promoted to first-class classes per the Q4a three-criterion test.

Decision: declare-once-reconcile vs mirror-the-JSON-tree

The two candidate strategies were evaluated against the core drivers — eliminating blank-node attachment and collapsing spanning leaves to one term per concept.

ODR dependency graph

ODR-0008 is gated by the identity crux (ODR-0005) and implements the foundation, enumeration, and overlay-profile ODRs; the full upstream dependency chain is shown below.