Property & Land: The Identity Crux

Context

PDTF v3 has no Property class. The thing every transaction is about is reconstructed at read time from scattered surfaces with zero schema-level joins: UPRN appears in four leaf paths (propertyPack.uprn, energyEfficiency.certificate.uprn, chain.onwardPurchase[].uprn, valuationComparisonData.propertyDetails[].uprn); address appears in many more; INSPIRE ID and title-linked address add further surfaces; the data dictionary defines uprn only as “a unique identifier for the property” and carries an isFirstRegistration leaf. In ontological terms this is a missing class with no identity criterion — the implicit-Property defect.

Council Session 001 (Q4) confirmed the diagnosis unanimously (12-0) and converged on a multi-class split, but explicitly deferred the identity criterion to this ODR as the programme’s gate. An ontology whose central endurant has no identity criterion is, in Guarino’s words, “not an ontology — it is a schema with RDF syntax.” Until the IC is settled and validated against ODR-0004’s diagnostic exemplars, ODR-0006/0007/0008 stay in planning.

Decision

Adopt the three-class Property pattern ratified by Council Session 005 (Phase 2 gate; B2 pilot consensus-mode hive-mind/byzantine; Queen Guarino, DA Allemang withdrew on 8 of 8 questions): three UFO Substance Kinds committed to DOLCE Endurant — opda:Property (physical Substance Kind; IC = spatial-material continuity with legal-record discontinuity override), opda:LegalEstate (legal-institutional Substance Kind; IC = rights-bundle persistence; may be unregistered), opda:RegisteredTitle (registry-record Substance Kind; IC = title-number lineage; carries distinct published-personal-data PII regime under HMLR open-register). Keyed operationally by SHACL/DASH uniqueness on UPRN with graceful degradation; UPRN succession captured by reified opda:UPRNSuccessionEvent materialised into the validation report via a SHACL-AF rule at sh:Info severity; joined via co-reference (never owl:sameAs); UPRN modelled as UFO Quality / contingent scheme-scoped identifier under prov:wasDerivedFrom succession — chosen because it is checkable, degrades gracefully for new-builds and pre-first-registration cases, avoids irreversible cross-context inference propagation, gives the unregistered-house case a coherent answer (which the 2-class collapse cannot), and gives RegisteredTitle instances a class-level discriminator for ICO Subject Access processing under the HMLR open-register lawful basis.

The diagram below shows the three Substance Kinds, their identity criteria, and the relationships between them.

Rules

Settled rules (the cure). These are normative for the Property module:

1. Explicit Property class. The four-surface, zero-join defect is restored to a class. No implicit-Property.
2. Three-class split (settled by Session 005 Q5; 6-2-1 FOR three-class with Davis + Cagle held-as-live dissent preserved): a physical opda:Property, a legal-institutional opda:LegalEstate (which may be unregistered at common law), and an HMLR registry-record opda:RegisteredTitle. Each is its own UFO Substance Kind with its own IC.
3. Operational key is SHACL/DASH uniqueness. dash:uniqueValueForClass true on opda:uprn is the primary, checkable mechanism: it fires a violation report and degrades gracefully when UPRN is absent.
4. owl:hasKey is optional/secondary — a semantic annotation valid only where UPRN is truly identifying. Never on a Role.
5. No owl:sameAs across the UPRN surfaces (unanimous — irreversible inference propagation). Join uses the key + SHACL co-reference, or a controlled opda:identifiesSameProperty.
6. UPRN is a contingent identifier, not the IC — operationally, a UFO Quality on opda:Property. Model retire/split/merge/re-issue via prov:wasDerivedFrom succession, with the chain materialised into the validation report via a SHACL-AF rule at sh:Info severity (§Operational specifications 6a).

Anti-patterns (forbidden):

• owl:sameAs between any two UPRN-bearing nodes.
• owl:hasKey (opda:uprn) as the sole identity mechanism (inert when UPRN is absent — Cagle’s S001 Q4 challenge, conceded by Guizzardi in S005 Q4).
• A keyed Role (a Proprietor has no identity qua Proprietor).
• Treating UPRN or address as the identity criterion (they are administratively contingent / a mode of presentation).
• Treating opda:RegisteredTitle as a UFO Mode of opda:LegalEstate (fails the temporal-extent test — RegisteredTitle exists before LegalEstate is vested + after LegalEstate is dissolved; not existence-dependent on LegalEstate).

Operational specifications (added by Session 005)

Session 005 (Full Council; B2 pilot consensus-mode hive-mind/byzantine; Queen Guarino; DA Allemang — withdrew on all 8 questions) discharges the gate conditions inline per ODR-0001 A9 §Per-kind discipline (b). The original numbered rules above stand; the operational specifications below state the (a) UFO/DOLCE meta-category, (b) IC over named hard cases, and (c) artefact realisation that the A9 amendment requires of every kind: pattern ODR.

2a. UFO/DOLCE category commitment per class (S005 Q1)

Each Kind committed to DOLCE Endurant + UFO Substance Kind (Sortal, Rigid, supplies own IC), with dct:source resolving to the upstream definition (Baker amendment — DCMI Usage Board discipline) and rdfs:subClassOf triples for machine-readable binding (Cagle amendment — DBpedia 2017 lesson on LLM consumer fallback):

Sub-kind granularity (Site / BuiltStructure / etc.) NOT committed in ## Rules per Allemang DA Q1 withdrawal condition. Deferred to ODR-0015 (Address & Geography) and to future pattern-extraction records per ODR-0001 A9 §Artefact identity test, gated on a named consumer query.

3a. IC for opda:Property over five named hard cases (S005 Q2)

IC = spatial-material continuity with legal-record discontinuity override (Kendall+Davis hybrid framing adopted; Allemang DA withdrawal condition (b) met). Authoritative source: Ordnance Survey AddressBase Plus Technical Specification §UPRN lifecycle (cited via dct:source with version pin per ODR-0004 §7a); HMLR title-register discontinuity rules as the override authority.

The diagram below shows how opda:Property identity behaves across the five named hard cases.

The five hard cases:

1. Demolition. Built structure entirely demolished + site bare → Property ceases. Replacement structure on same site → new opda:Property p₂ with prov:wasDerivedFrom to predecessor.
2. Subdivision. Property subdivided into two or more units → predecessor ceases; each new unit is a new Property with prov:wasDerivedFrom chain.
3. Merger. Two adjacent Properties merged → both predecessors cease; merged unit is new Property with prov:wasDerivedFrom to both.
4. Replacement (rebuild on same plot). Default = new Property iff the legal record asserts discontinuity (HMLR title-closure + re-registration, OR new UPRN issuance with no prov:wasDerivedFrom chain). Routine knock-down-rebuild without registry discontinuity preserves identity — matches conveyancer pragmatic practice (Allemang’s third hard case). Heritage exception for listed buildings via SHACL profile (ODR-0010 territory).
5. Boundary modification. Easement granted, transfer-of-part, or other legal-boundary change → Property persists. The IC is physical, not legal; the boundary change affects opda:LegalEstate, not opda:Property.

Invariance under coordinate-system revision. The IC reads spatial-extent topology, not coordinate values. OS coordinate revisions (OSGB36 → ETRS89, sub-metre) preserve topology; the IC is invariant.

SHACL operationalisation (Cagle surrogates): spatial-material continuity is not directly SHACL-checkable, so the IC is operationalised via three surrogate predicates: (a) opda:hasGeometry (deferred to GeoSPARQL — ODR-0015); (b) opda:parcelIdentifier (INSPIRE ID) as stable proxy; (c) UPRN succession via reified opda:UPRNSuccessionEvent (§6a below).

3b. IC for opda:LegalEstate over five named hard cases (S005 Q3)

IC = rights-bundle persistence. Authoritative source: HM Land Registry Practice Guide 1 — First Registrations and Practice Guide 16 — Cancellation of registered titles (cited via dct:source with version pin).

1. Estate transfer. Freehold transferred A→B → same LegalEstate persists; proprietorship is a Role borne by different bearers across time (per ODR-0006).
2. Estate enlargement. Leasehold enlarged into freehold (statutory) → new LegalEstate (rights-bundle has changed kind); prov:wasDerivedFrom chains to predecessor.
3. Estate determination. Leasehold determined on lease expiry → ceases; freehold reverts to existing freeholder estate.
4. Charges and easements. Do NOT change identity; modelled as UFO Modes inhering in the estate (per ODR-0007 / ODR-0008 elaboration).
5. First registration. Previously-unregistered estate (existing at common law) persists as the same individual when registration completes; first registration is a registry-side event, not an estate-side change.

3c. IC for opda:RegisteredTitle over five named hard cases (S005 Q3)

IC = title-number lineage + registry-event history. Authoritative source: HMLR Practice Guide 1, PG 16, PG 40 — HM Land Registry plans (cited via dct:source with version pins). Every title-lifecycle event captured as a reified prov:Activity with explicit prov:wasDerivedFrom / prov:wasInvalidatedBy triples (Cagle amendment — NOT as rdfs:comment describing what happened); SHACL-checkable.

1. Title opening (first registration). New RegisteredTitle prov:wasGeneratedBy a registration activity. The third entity with its own lifecycle Hendler named in S001 Q4.
2. Title closure. Closed title retains title-register identity (title number preserved in historical record); lifecycle state transitions to closed via reified PROV event. The LegalEstate it recorded may persist (under a new title) or cease.
3. Title merger. Two RegisteredTitles merged → both predecessors closed; one new title opened with prov:wasDerivedFrom chains to both.
4. Transfer between registers. Title moves between HMLR districts (rare). Title-number changes; prov:wasDerivedFrom chains new to old; underlying LegalEstate persists.
5. Title reissue on corrupt-plan replacement. Reissued under new title-number; same prov:wasDerivedFrom discipline; same LegalEstate.

SHACL invariant (Cagle): a title with prov:wasInvalidatedBy MUST NOT appear as the object of opda:identifiesSameProperty to a current Property.

6a. UPRN succession — SHACL-rule materialisation (S005 Q4 — Cagle amendment)

Rule 6 is operationalised via a SHACL-AF rule that materialises the succession-chain into the validation report. Without this, the literal-pair form (opda:previousUPRN) is decorative against LLM consumers (Hellmann et al. DBpedia 2017 lesson on fallback to owl:sameAs heuristics).

The rule sits in opda-shapes.ttl (NOT the annotation graph — per S004 Q3 keying); produces sh:Info severity (succession is correct behaviour, not violation); consumed by LLM tooling and SHACL validators uniformly:

opda:UPRNSuccessionRule a sh:NodeShape ;
    sh:targetClass opda:Property ;
    sh:sparql [
        sh:select """
            SELECT $this ?currentUPRN ?previousUPRN WHERE {
                $this opda:uprn ?currentUPRN .
                OPTIONAL { $this opda:previousUPRN ?previousUPRN }
            }
        """ ;
        sh:message "Property {$this} has UPRN succession chain: {?currentUPRN} ← {?previousUPRN}"
    ] .

Canonical succession-reification. The reified opda:UPRNSuccessionEvent (resource form) is canonical per Gandon’s W3C-side recommendation — own URI, dereferenceable identity, audit trail. The literal opda:previousUPRN pair is retained as denormalised convenience for dash:uniqueValueForClass-style stale-reference checks. Both coexist; the reified event is authoritative.

Three-part operational test (falsifiable per ODR-0004 §6a discipline):

1. Duplicate-UPRN test. Two opda:Property instances with the same opda:uprn literal MUST produce sh:resultSeverity sh:Violation.
2. Graceful-degradation test. A opda:Property with no opda:uprn triple MUST produce NO SHACL violation from dash:uniqueValueForClass (unregistered-pre-first-registration exemplar discharges this).
3. UPRN-succession-chain test. opda:Property with opda:uprn AND opda:previousUPRN MUST be traversable by SPARQL returning both UPRNs as identifying the same Property (flat-with-split-uprn exemplar discharges this with the SHACL rule above firing sh:Info).

6b. Address-as-identifier prohibition + ODR-0015 routing (S005 Q6)

opda:Property is identified neither by address nor by mode-of-presentation. Address modelling is routed to ODR-0015 (Address & Geography — Reduced Council, Phase 2.6 gate spawned by Scope-Check 1 Q7a). ODR-0005 commits only to:

• Address is not an IC for opda:Property (Guarino S001 Q4 unanimous framing).
• Address is not a key for opda:Property (Anti-pattern — would produce false-positive violations on similar-but-not-identical address strings and false-negative misses on multiple address-presentations of one Property).
• opda:Property opda:hasAddress is the join predicate to whatever Address resource structure ODR-0015 ratifies (Cagle pre-commitment — opda:hasAddress is uniform; the Address resource’s class and IC are ODR-0015’s territory).

The Mode-vs-Resource question (UFO Mode of presentation, or opda:Address resource Kind with opda:addressVariant) is NOT decided in ODR-0005; ODR-0015 resolves with explicit DPV-pattern consideration (Baker+Pandit constraint carry — Address-as-mode means PII attaches to mode-instances; Address-as-resource means PII attaches to resource-instances).

7a. Diagnostic exemplar set with per-exemplar verdict walkthrough (S005 Q7)

The three canonical exemplars (authored 2026-05-27 per ODR-0004 §8a between-session prep) pass under the three-class commitment + spatial-material continuity IC + UPRN-as-Quality-with-PROV-succession + Address-as-routed-to-ODR-0015. Each is cited per ODR-0004 §8a + Pandit’s amendment (path + one-line description of named hard case):

Exemplar amendments scheduled (next author-only follow-up session — non-blocking):

• Amend exemplar 1: add opda:LegalEstate individual explicitly (3-class completeness).
• Amend exemplar 2: add common-law opda:LegalEstate individual explicitly (discharges Kendall’s cardinality-test requirement; LegalEstate-without-RegisteredTitle case made manifest).
• Amend exemplar 3: scope-note notes reified opda:UPRNSuccessionEvent is canonical succession form (Gandon W3C-side recommendation).

expected-report.ttl pairing deferred to a follow-up author-only session when the SHACL shapes graph crystallises; each exemplar becomes a CI regression test per ODR-0004 §8a discipline.

Future exemplar growth (non-gate-critical, recorded for next session):

• multi-title-flat.ttl (Hendler’s extension — model both leasehold and freehold titles on one physical flat for 3-class cardinality reinforcement).
• duplicate-uprn-data-error.ttl (Cagle’s data-error case — pressure-tests dash:uniqueValueForClass violation firing).
• Cardinality-test exemplar variants (e.g. unregistered Manor; pre-1990 unregistered freehold outside compulsory triggers).

8a. Gate clearance status (S005 Q8)

Council-side gate cleared. All four original gate conditions discharged:

1. Class cardinality settled — 3 classes (§2a above; Q5 6-2-1 verdict; Davis + Cagle held-as-live dissent preserved).
2. DOLCE category commitment per class settled — all three commit to Endurant / UFO Substance Kind (§2a).
3. IC over hard cases stated — spatial-material continuity for Property (§3a); rights-bundle persistence for LegalEstate (§3b); title-number lineage for RegisteredTitle (§3c).
4. UPRN’s precise status settled — both checkable SHACL/DASH key AND contingent administrative identifier under PROV-O succession (§6a); UPRN is a UFO Quality, not the IC (S005 Q4).

Artefact-level status: accepted. The opda: namespace string is ratified (ODR-0004 §Rules.1, 2026-05-27 — greenfield ratification; no WG), and ODR-0004 is accepted, so ODR-0005 follows: accepted. Generator output for opda:Property, opda:LegalEstate, opda:RegisteredTitle, and all property predicates may still carry dct:status "draft" in the ontology header as a publication-grade marker — that is independent of record ratification, which is now complete.

Downstream consequence (operational at deliberative level even with namespace block):

• ODR-0006 (Agents & Roles), ODR-0007 (Transactions & Lifecycle), ODR-0015 (Address & Geography) UNBLOCKED. May proceed to their Council sessions immediately.
• ODR-0008 (Property Descriptive Attributes) DEFERRED until cardinality landing crystallises (Kendall+Davis joint amendment — the 935-annotated-leaf layer’s leaf-to-class mapping depends on the 3-class commitment).
• ODR-0009 (Claims, Evidence & Provenance), ODR-0010 (Overlay Profile Mechanism), ODR-0012 (Data-Governance Layer), ODR-0013 (SHACL Validation & Severity) UNAFFECTED (their gates are upstream-independent of ODR-0005; they inherit specific load-bearing inputs — see Consequences).

Alternatives

• One opda:Property Kind with alternative identifiers + SHACL co-reference (Kendall, FIBO-LEI pattern) — strains when physical referent and legal interest diverge (multi-title flat, commonhold), risking re-conflation of physical and legal identity in one class.
• Two classes: Property (physical) + LegalEstate (Allemang) — does not give the Land Registry’s record its own identity, which Hendler/Guizzardi argue is a third thing with its own lifecycle.
• Three classes: + RegisteredTitle (Hendler / Guizzardi) — adds modelling and validation surface; the 2-vs-3 boundary is exactly what the exemplars must justify rather than assume.
• Two endurants with explicit ICs: Site/BuiltStructure + LegalEstate (Guarino) — most demanding to author and validate; the time-indexed realises/vests-in relation introduces OWL-Time dependency (ODR-0014) the simpler splits avoid.
• owl:hasKey on the rigid Kind as primary — only licenses inference and is inert for a consumer whose record has no UPRN; does nothing for the new-build / first-registration case.
• owl:sameAs across UPRN surfaces — propagates every context’s properties onto every other, irreversibly under inference (unanimous rejection).

Consequences

Added by Session 005 — Allemang DA full withdrawal (8 of 8 questions); Davis + Cagle held-as-live dissent on Q5 preserved.

• Namespace ratified; record accepted. The opda: namespace string is ratified (ODR-0004 §Rules.1, 2026-05-27 — greenfield; no WG), so the inherited block is lifted and ODR-0005 is accepted. Generator output may still carry dct:status "draft" as a publication-grade marker; downstream pattern ODRs inherit accepted through their depends-on chains.
• Held-as-live dissents on Q5 (3-class commitment). Davis preserves the 2-class-with-RegisteredTitle ⊑ LegalEstate-upgradeable position with the named re-open trigger: if downstream sessions (S006/S007/S008) surface a case where 3-class is operationally net-negative against the BASPI5 round-trip, the dissent is the re-open trigger. Cagle preserves the 2-class-with-commonhold-spawn-rule position: if a commonhold exemplar surfaces in S006 or S007, the §6 spawn rule fires and ODR-0005a/0005b is created. Neither dissent blocks the verdict; both preserve a re-open path.
• A9 pressure-test passes. ODR-0005 is the first kind: pattern ODR to discharge under ODR-0001’s A9 amendment (the per-kind discipline ratified 2026-05-27). Its ## Rules states inline: (a) three UFO Substance Kinds + DOLCE Endurant (§2a); (b) IC over five named hard cases each (§3a/3b/3c); (c) artefact realisation via SHACL/DASH + PROV-O + opda:identifiesSameProperty (§6a + Rules 3-5). The methodology’s first pressure-test holds; the per-kind discipline becomes the template downstream kind: pattern ODRs (0006, 0007, 0008, 0015) inherit.
• B2 pilot verdict: EXTEND CAUTIOUSLY. The consensus-mode: hive-mind/byzantine two-artefact discipline (narrative + structured tally) is recommended for Sessions 011 Q8 and 015 (Reduced Council). Full evaluation in the session transcript §B2 pilot — retire-or-extend evaluation. Three-pilot threshold for EXPAND (full adoption) requires S011 Q8 + S015 corroborating evidence.

The diagram below shows which downstream ODRs are unblocked, deferred, or inherit specific inputs from the ODR-0005 three-class commitment.

Downstream ODR inheritance (deliberative level, irrespective of namespace block):

• ODR-0006 (Agents & Roles). Inherits the IC discipline pattern (SHACL primary; no owl:sameAs; PROV-O for administrative-identifier succession) for Person/Organisation identity. The 3-class precedent applies to its own per-kind discipline (Person IC over name-change, gender-recognition, death; Organisation IC over merger, demerger, dissolution).
• ODR-0007 (Transactions & Lifecycle). Inherits the 3-class commitment as load-bearing: a Transaction is against a LegalEstate; the RegisteredTitle provides the registry-side record; the Property is the physical referent. OWL-Time intervals attach to LegalEstate (tenure terms) and RegisteredTitle (registry-event timestamps).
• ODR-0008 (Property Descriptive Attributes). DEFERRED until cardinality landing crystallises — the 935-annotated-leaf layer’s leaf-to-class mapping depends on which class each descriptive attribute attaches to (encumbrances → LegalEstate; title-events → RegisteredTitle; physical condition → Property).
• ODR-0009 (Claims, Evidence & Provenance). Inherits the PROV-O succession discipline as a shared substrate; no direct gate-blocking dependency. Cross-references the reified opda:UPRNSuccessionEvent pattern (§6a) as a related prov:Activity reification pattern.
• ODR-0010 (Overlay Profile Mechanism). The Cagle SHACL-AF succession rule (§6a) may be included or excluded by overlay profile; the consumer chooses whether it wants the succession chain in its validation report.
• ODR-0012 (Data-Governance Layer). Inherits two load-bearing inputs from S005: (i) the PII regime distinction between RegisteredTitle (HMLR-published personal data; ICO public-task lawful basis) and LegalEstate (private until registered) — Pandit’s Q3 + Q5 amendments; (ii) the PROV-O succession trail as PII-history trail under GDPR Art. 5(1)(d) accuracy principle — Pandit’s Q2 + Q4 amendments. ODR-0012’s DPV co-annotation authoring (per Scope-Check 1 Q5 refinement) consumes both.
• ODR-0013 (SHACL Validation & Severity). The Cagle SHACL-AF succession rule sits at sh:Info severity (§6a); ODR-0013 ratifies the severity tier and the rule’s placement in the shapes graph (not the annotation graph per S004 Q3 keying).
• ODR-0015 (Address & Geography). Unblocked. Inherits the co-reference discipline (opda:identifiesSameProperty predicate; opda:hasAddress join relation pre-committed); resolves the Mode-vs-Resource question with explicit DPV-pattern consideration (Baker+Pandit Q6 constraint).

Operational deliverables (when generator-first stack lands per ODR-0004):

• property.ttl (three classes with DOLCE categories, ICs, keys per §2a/3a/3b/3c/6a).
• SHACL co-reference + uniqueness shapes (opda:identifiesSameProperty; dash:uniqueValueForClass on opda:uprn).
• The Cagle SHACL-AF succession rule (§6a) in opda-shapes.ttl.
• The three exemplars with expected-report.ttl pairings (per ODR-0004 §8a).
• A migration note for the four existing UPRN references in the PDTF v3 base schema.

Re-open triggers (recorded for future sessions):

• Davis’s BASPI5-round-trip negative consequence trigger (3-class is net-negative for round-trip).
• Cagle’s commonhold exemplar trigger (commonhold surfaces in S006/S007 → §6 spawn rule fires).
• Allemang DA’s S001 Q4 consumer-side query non-discovery trigger: if 18 months of downstream sessions produce zero consumer queries that need the 3-class discrimination, his S005 Q5 dissent (now formally withdrawn) becomes a re-open consideration.

References

• Target versions: RDF 1.2 and SHACL 1.2, per the Core-tier pin in ODR-0002.
• Vocabularies: Core (OWL/RDFS/XSD); SHACL + DASH (dash:uniqueValueForClass) + SHACL-AF (sh:rule / sh:sparql for §6a succession-chain materialisation); PROV-O (prov:wasDerivedFrom, prov:wasGeneratedBy, prov:wasInvalidatedBy); OWL-Time (Conditional, ODR-0014 retired → ODR-0002 §Change log) if interval-valued tenure is modelled here or deferred to ODR-0007. Term semantics and dct:source follow the term-sourcing convention in ODR-0004 §7a.
• The four UPRN surfaces: propertyPack.uprn, energyEfficiency.certificate.uprn, chain.onwardPurchase[].uprn, valuationComparisonData.propertyDetails[].uprn; address and INSPIRE ID add further surfaces.
• Foundational ontology: Guizzardi 2005, Ontological Foundations for Conceptual Modeling with Applications, Ch. 4 (UFO Substance Kind / Role / Phase / Relator / Mode / Quale taxonomy); Masolo, Borgo, Gangemi, Guarino, Oltramari 2003, The WonderWeb Library of Foundational Ontologies, D18 (DOLCE — Endurant / Perdurant / Quality / Quale); Guarino & Welty 2002, 2009, An Overview of OntoClean (meta-properties — Rigidity, Identity, Unity, Dependence); Searle 1995, The Construction of Social Reality (legal-institutional objects).
• W3C standards: Hayes & Patel-Schneider 2014, RDF 1.1 Semantics §6 (owl:sameAs propagation); Moreau & Missier eds. 2013, PROV-O Recommendation §3 (prov:wasDerivedFrom, prov:wasGeneratedBy, prov:wasInvalidatedBy); Knublauch & Kontokostas eds. 2017, SHACL Recommendation §4 (Core); SHACL-AF (sh:rule, sh:sparql); DASH (dash:uniqueValueForClass).
• Authoritative external sources (cited via dct:source with version pin per ODR-0004 §7a): Ordnance Survey AddressBase Plus Technical Specification §UPRN lifecycle (for opda:Property IC spatial-material continuity surrogate authority); HMLR Practice Guide 1 — First Registrations, PG 16 — Cancellation of registered titles, PG 40 — HM Land Registry plans (for opda:LegalEstate and opda:RegisteredTitle IC stewardship); ICO Guidance on Public Authorities Lawful Bases 2023 §HMLR open-register (for opda:RegisteredTitle PII regime).
• Diagnostic exemplars (per ODR-0004 §8a; authored 2026-05-27 between-session prep):
  • source/03-standards/ontology/exemplars/registered-freehold-house.ttl — baseline (UPRN present, freehold title registered, single proprietor).
  • source/03-standards/ontology/exemplars/unregistered-pre-first-registration-house.ttl — UPRN absent + LegalEstate-without-RegisteredTitle (Cagle graceful-degradation challenge + Guarino IC-must-work-without-legal-anchor + Pandit PII-regime-transition lifecycle event).
  • source/03-standards/ontology/exemplars/flat-with-split-uprn.ttl — UPRN succession via prov:wasDerivedFrom; physical identity persists across re-numbering (§6a SHACL rule discharge).
• Related: programme anchor ODR-0003; foundation ODR-0004; methodology ODR-0001 §What an ODR records (per-kind discipline) (A9 amendment — this ODR is the first kind: pattern to discharge under it). Unblocked downstream modules: ODR-0006 (shared Person/Organisation identity), ODR-0007 (3-class commitment is load-bearing), ODR-0015 (Address modelling inherits opda:hasAddress and DPV-pattern constraint). Deferred until cardinality crystallises: ODR-0008. Downstream consumers of S005 amendments: ODR-0009 (PROV-O succession pattern), ODR-0010 (succession rule inclusion in profile), ODR-0012 (PII regime distinction + PII-history trail), ODR-0013 (succession rule severity tier).
• Council deliberation:
  • session-001 Q4 (the crux diagnosis; multi-class convergence; deferral to this session).
  • session-005 — Property & Land: The Identity Crux (2026-05-27; Full Council; B2 pilot consensus-mode hive-mind/byzantine; Queen Guarino; DA Allemang — 8 of 8 questions withdrawn). 8 questions: Q1 9-0 FOR Endurant + Substance Kind; Q2 9-0 FOR spatial-material with legal-record discontinuity override; Q3 9-0 FOR distinct ICs (LegalEstate rights-bundle + RegisteredTitle title-number lineage); Q4 9-0 FOR both (SHACL key + PROV-O contingent) + Cagle SHACL-AF rule; Q5 6-2-1 FOR 3-class (Davis + Cagle held-as-live); Q6 9-0 FOR deferral to ODR-0015; Q7 9-0 PASS with per-exemplar verdict walkthrough; Q8 9-0 FOR deliberative clearance with namespace block. Held dissents preserved: Davis (BASPI5-round-trip re-open trigger), Cagle (commonhold spawn-rule trigger). B2 pilot verdict: EXTEND CAUTIOUSLY (recommended for S011 Q8 + S015). Per-expert working notes under council/session-005-property-land-identity-crux/.
• Ratification provenance: session-005 (2026-05-27; Queen Guarino; DA Allemang — full withdrawal). Phase 2 Council gate cleared substantively; formal status: accepted awaits WG namespace ratification (inherited from ODR-0004).