SHACL-AF Non-Blocking Data-Quality Rules

Context and Problem Statement

A pattern has emerged across four kind: pattern ODRs ratified through 2026-05-27: each authored a SHACL-AF rule (sh:rule / sh:sparql) that materialises a non-blocking data-quality assertion — succession, deprecation, lineage — into the validation report at sh:Info or sh:Warning severity, NOT as sh:Violation. The data being asserted is correct under its temporal or contextual scope (UPRN succession is administrative; deprecation is a lifecycle state; INSPIRE succession is rare-but-real); the rule is informative, not normative-breaking.

The four citing sites:

1. ODR-0005 §6a — UPRN succession chain (Cagle Q4 amendment, S005). Materialises opda:previousUPRN → opda:uprn chain at sh:Info; rebuts Hellmann et al. (DBpedia 2017) LLM-fallback-to-owl:sameAs failure mode for identifier succession.
2. ODR-0009 (Claims, Evidence & Provenance — when S009 runs). Anticipated: PROV-O Activity reification + prov:wasDerivedFrom chain materialisation for evidence-collection events.
3. ODR-0015 §4a — INSPIRE Identifier / OS AddressBase succession (S015 Q4); re-instantiates the §6a pattern for the Address Kind’s contingent identifier (per S005’s Quality-on-Substance-Kind precedent).
4. ODR-0011 §5a — Concept deprecation-chain (Cagle Q5 amendment, S011). Materialises owl:deprecated true + dct:isReplacedBy chain at sh:Info (with-succession) or sh:Warning (without-succession).

Per ODR-0001 A9 §Artefact identity test — the fourth-citing-site threshold for pattern-extraction is satisfied. S011 §Consequences flagged the spawn-rule as fired. This ODR extracts the pattern as a reusable artefact-engineering decision; the four citing sites become implements: of it; future SHACL-AF rule authoring re-instantiates the pattern rather than re-deciding the discipline per ODR.

The pattern is kind: pattern per ODR-0001 A9 §What an ODR records (a)/(b)/(c) discipline: UFO/DOLCE meta-category (Method/plan code per ODR-0011 §8a — the rule is a procedural plan for materialising data-quality assertions), IC over named hard cases (rule severity; rule placement in graph; rule consumption by tooling), artefact realisation (sh:rule / sh:sparql SHACL-AF Turtle template).

Considered Options

• Option A (chosen) — SHACL-AF sh:rule/sh:sparql in opda-shapes.ttl at sh:Info/sh:Warning severity with machine-parseable sh:message. The canonical pattern extracted as a reusable artefact from four citing sites.
• Option B — Materialise data-quality assertions in the annotation graph (opda-annotations.ttl). Rejected per ODR-0004 §3a CI test 1: SHACL rules in the annotation graph break the three-graph separation; LLM consumers querying the annotation graph would receive shape-graph content as if it were advisory annotations, corrupting both layers.
• Option C — Use OWL reasoning + owl:propertyChainAxiom to materialise the succession chain. Rejected per ODR-0005 Rule 5 anti-pattern (no owl:sameAs-equivalent propagation across contexts). OWL property chains produce inferred triples that propagate irreversibly under reasoning; the use case is informative materialisation, not normative-equivalence assertion.
• Option D — Encode the data-quality assertion in rdfs:comment only. Rejected per Hellmann et al. (DBpedia 2017) LLM-fallback failure mode — natural-language rdfs:comment is consumed by LLM heuristics, which fail on rename/paraphrase/translation.
• Option E — Bake the rule into each consuming ODR without pattern-extraction. Rejected by ODR-0001 A9 §Artefact identity test fourth-citing-site threshold — the pattern has crossed the threshold for shared abstraction; baking it into each ODR creates four parallel-but-divergent rule authorings.

The diagram below maps each considered alternative to the decision driver that disqualified it, with the chosen pattern shown as the accepted outcome.

Decision Outcome

Chosen option: “SHACL-AF sh:rule/sh:sparql in opda-shapes.ttl at sh:Info/sh:Warning severity”, because the fourth-citing-site threshold is satisfied and the alternative placements each break a load-bearing constraint (three-graph separation, no-owl:sameAs propagation, machine-readability, or non-duplication of discipline).

The diagram below illustrates how a SHACL-AF non-blocking rule routes a data-quality assertion to sh:Info/sh:Warning rather than sh:Violation, contrasting it with ordinary normative-blocking SHACL constraints.

Adopt the SHACL-AF non-blocking data-quality rules pattern as the canonical mechanism for materialising data-quality assertions that are informative, not normative-breaking: a sh:rule (or sh:sparql form) on the targeted class, returning the assertion’s value via SELECT $this ?fact …, with sh:severity sh:Info (state-with-substantive-succession) or sh:Warning (state-without-succession), placed in the shapes graph (opda-shapes.ttl per ODR-0004 §3a). The rule’s output is machine-consumable data — read by SHACL validators, LLM tooling (per Hellmann et al. DBpedia 2017 LLM-fallback rebuttal), odr-review lint extensions, audit-trail consumers. The rule is never sh:Violation severity (Violation is reserved for normative-breaking; the assertions this pattern materialises are correct under their temporal/contextual scope).

Consequences

• Four-site implements: retrofitting. ODR-0005 §6a, ODR-0009 (when S009 ratifies its PROV-O rule), ODR-0015 §4a, ODR-0011 §5a all add ODR-0017 to their implements: frontmatter and cite this pattern in their ## References. The retrofit is a follow-up author-only edit; flagged as housekeeping for the next /loop fire or Queen-convened session.
• A9 pressure-test continues to operate. This is the first kind: pattern ODR that is itself a pattern-extraction record (not a domain-modelling pattern). The (a)/(b)/(c) discipline applies; this ODR discharges all three (Method/plan code UFO category; five named hard cases for rule identity; Turtle template artefact).
• odr-review lint extension. Beyond the existing planned extensions (per ODR-0004 §Consequences), the lint should verify: any SHACL-AF rule declaring sh:Info or sh:Warning severity is implements: ODR-0017; conversely, any ODR implements: ODR-0017 MUST place its SHACL-AF rule in opda-shapes.ttl (not annotation graph) AND MUST use the §1a template structure.
• Future succession patterns. ODR-0006 (Agents & Roles, Phase 3a) may produce a fifth citing site (e.g. NI-number renumbering; passport-renewal succession for Person identity). When it does, ODR-0017 is the canonical pattern to implements:; the new rule re-instantiates the template rather than re-deciding the discipline.
• Namespace ratified; record accepted. The inherited ODR-0004 namespace block is lifted (the opda: string was ratified 2026-05-27 — greenfield; no WG), so ODR-0017 is accepted. Generator output for the rule’s opda: declarations may still carry dct:status "draft" as a publication-grade marker, independent of record ratification.

More Information

• Methodology: ODR-0001 §What an ODR records (per-kind discipline) — A9 amendment 2026-05-27; §Artefact identity test (the fourth-citing-site threshold this ODR satisfies); ODR-0011 §8a (Method/plan code UFO category source).
• Foundation: ODR-0004 §3a (three-graph separation — shape lives in opda-shapes.ttl); §6a (generator-first deterministic-emission discipline).
• W3C / spec: SHACL Core Recommendation §5.2.6 (SPARQL-based constraints); SHACL Advanced Features (sh:rule, sh:Rule) — W3C Working Group Note; SHACL Core §6.5 (severity); PROV-O Recommendation (Moreau & Missier 2013); RDF 1.1 Semantics (Hayes & Patel-Schneider 2014) §6 (owl:sameAs).
• Foundational ontology: Guizzardi 2005 Ontological Foundations Ch. 4 (UFO Method/plan codes); Guizzardi & Wagner 2010 (action-modelling).
• AI-RDF citation: Hellmann et al. 2017 DBpedia 2017 release notes — LLM fallback to owl:sameAs / heuristic class-name matching when assertions are in rdfs:comment only.
• Citing sites (implements: retrofit pending):
  • ODR-0005 §6a — UPRN succession-chain rule (Cagle S005 Q4 amendment).
  • ODR-0009 — PROV-O Claims/Evidence rule (anticipated when S009 ratifies).
  • ODR-0015 §4a — INSPIRE / OS AddressBase succession (S015 Q4).
  • ODR-0011 §5a — Concept deprecation-chain rule (Cagle S011 Q5 amendment).
• Council deliberation provenance: spawned by session-011 §Synthesis + §Consequences (fourth-citing-site spawn-rule fires); authored as Author-only follow-up to S011’s closure per ODR-0001 §Self-amendment process + §Artefact identity test.
• Related ODRs: programme anchor ODR-0003; methodology ODR-0001 §What an ODR records (per-kind discipline for kind: pattern).

The graph below shows ODR-0017’s dependency and implementing relationships as declared in the frontmatter.

Rules

These rules constrain every implements: of this pattern.

1. sh:rule or sh:sparql form. The rule is authored as either a sh:Rule (SHACL Advanced Features Recommendation §2) or a sh:sparql constraint with sh:select body (SHACL Core §5.2.6 SPARQL-based constraints). Both forms admissible; choice depends on whether the materialised triples need to enter the data graph (use sh:Rule) or only the validation report (use sh:sparql).
2. Severity at sh:Info or sh:Warning, NEVER sh:Violation. The data is correct; the rule is informative. sh:Info for assertions with substantive succession recorded (prov:wasDerivedFrom / dct:isReplacedBy chains present). sh:Warning for assertions without substantive succession (deprecation-without-replacement; retirement-without-successor).
3. Placement in shapes graph (opda-shapes.ttl). Per ODR-0004 §3a three-graph separation, the rule lives in the shapes graph, NOT the annotation graph (opda-annotations.ttl). The CI test ASK { GRAPH opda:annotations { ?s a sh:NodeShape } } returns false; this rule’s sh:NodeShape declaration is in opda:shapes.
4. SELECT $this ?fact ?succession SPARQL skeleton. The rule’s SPARQL body returns at minimum the target node ($this) and the materialised assertion. The sh:message template references the captured variables for human-readable reporting AND machine-readable downstream parsing.
5. sh:message is machine-parseable. The message template uses {?var} placeholders that the SHACL validator interpolates; downstream tooling (LLM consumers, lint extensions) parses the rendered message to extract the structured assertion. AVOID natural-language paragraphs in sh:message; PREFER structured key-value or template-literal form.
6. No owl:sameAs materialisation. A non-blocking data-quality rule MUST NOT produce owl:sameAs triples (inherits ODR-0005 Rule 5 anti-pattern — owl:sameAs propagates irreversibly under reasoning). Materialise via prov:wasDerivedFrom, dct:isReplacedBy, skos:exactMatch, or opda:identifiesSameProperty per the consuming ODR’s discipline.
7. Consuming ODR cites this pattern via implements:. Each consuming ODR declares implements: [..., ODR-0017] in its frontmatter (alongside its other implements: of ODR-0003). The ## References section cites this ODR’s pattern URL for the authoring discipline.

Operational specifications

1a. Canonical template (SHACL-AF rule form)

opda:<DomainQuality>NonBlockingRule a sh:NodeShape ;
    sh:targetClass <opda:TargetKind> ;
    sh:sparql [
        sh:select """
            SELECT $this ?currentFact ?priorFact WHERE {
                $this <opda:currentPredicate> ?currentFact .
                OPTIONAL { $this <opda:priorPredicate> ?priorFact }
            }
        """ ;
        sh:severity sh:Info ;     # sh:Warning if no substantive succession
        sh:message "{$this} <opda:domain-quality-relationship> {?currentFact} ← {?priorFact} (where defined)"
    ] .

Per ODR-0004 §3a three-graph separation: the rule sits in opda-shapes.ttl; the data graph (e.g. opda-instances.ttl or per-Property graphs) carries the data the rule reads; the validation report is the rule’s output channel.

2a. Three-tier severity decision rule

The following flowchart traces the evaluation path of a single SHACL-AF rule instance from the shapes graph through the validator to its downstream consumers.

3a. Machine-consumability requirement

Per Hellmann et al. (DBpedia 2017) LLM-fallback rebuttal (Cagle S005 §6a + S011 §5a citations): the rule’s output MUST be machine-parseable by:

1. SHACL validators (the canonical consumer — produces sh:ValidationReport triples; consumer queries sh:resultMessage and sh:focusNode).
2. odr-review lint extensions — reads the rule’s source from opda-shapes.ttl; verifies severity is in {sh:Info, sh:Warning} (rejects sh:Violation); verifies placement in shapes graph; verifies sh:message template uses placeholder form.
3. LLM tooling — queries the validation report for sh:resultMessage literals; parses the structured template form for the non-blocking-quality assertion content; substitutes the assertion for rdfs:comment-based natural-language fallback (which Hellmann et al. documented as failing on rename/paraphrase/translation).
4. Audit-trail consumers — read the sh:Info/sh:Warning entries as data-quality lineage records; correlate with the data graph’s reified event resources.

4a. UFO/DOLCE meta-category — Method/plan code (A9 (a) discharge)

Per ODR-0011 §8a’s seven-category UFO framework, this pattern is a Method/plan code — the SHACL-AF rule is a procedural plan for materialising a data-quality assertion into the validation report. The plan is reusable across domains (UPRN succession; deprecation; INSPIRE re-issue; future Person-ID succession). The plan’s executor is the SHACL-AF-aware validator (the canonical consumer); other consumers (lint, LLM, audit) read the executed plan’s output.

dct:source on the UFO category: Guizzardi & Wagner 2010 (action-modelling / method-codes in UFO-A) + Guizzardi 2005 Ch. 4 + ODR-0011 §8a (Council-authored SKOS-binding) + ODR-0017 (this pattern’s plan-code specialisation).

5a. IC over named hard cases (A9 (b) discharge)

A SHACL-AF non-blocking-data-quality rule r₁ at time t₁ and a candidate-individual rule r₂ at time t₂ > t₁ are the same individual iff (i) their sh:targetClass is the same; (ii) their sh:select SPARQL body is structurally equivalent (same WHERE-clause patterns modulo variable renaming); (iii) their severity is the same. Under the following hard cases:

1. Rule extension. A rule’s SPARQL body gains a new OPTIONAL clause without changing the existing patterns → same individual (extension preserves identity).
2. Severity adjustment. A rule’s severity changes between sh:Info ↔ sh:Warning → same individual (severity tier is a refinement, not an identity change). Severity changing to sh:Violation → rule ceases to exist under this pattern; a new (non-pattern) SHACL constraint replaces it.
3. Target-class change. Rule’s sh:targetClass changes → new individual; prov:wasDerivedFrom chains the new rule to the predecessor.
4. Message-template refinement. The sh:message template is rephrased without changing variable references → same individual.
5. Graph relocation. Rule moves from one shapes graph to another (e.g. extracted from one ODR’s profile shapes into a shared shapes module) → same individual; the move is dct:isReplacedBy (in the OLD location’s deprecation) + prov:wasGeneratedBy (in the new location’s instantiation).

6a. Artefact realisation (A9 (c) discharge)

The artefact realisation is the Turtle SHACL-AF rule above (§1a), placed in opda-shapes.ttl per ODR-0004 §3a. The rule is emitted by the generator (per ODR-0004 §6a deterministic-emission discipline) reading from a rule-source declaration; the rule’s structure follows the §1a template; the generator MAY parameterise the rule via inputs (target-class, predicates, severity) so each implements: site supplies only the parameters, not the full Turtle.