Coventry And Warwickshire Heritage Functionality Evaluation

Report Purpose And Headline

This is an exemplar evaluation of what OKF Explorer can do with a complete, explicitly bounded set of heritage sources. It is not a legal register, a condition survey or a replacement for Historic England.

This report describes stable candidate content and the gates required to promote it. It deliberately does not carry a current deployment status, workflow run identifier or observation timestamp. Those time-sensitive facts belong in an independently signed promotion envelope, so observing a candidate does not change the candidate that was observed.

The source-defined NHLE denominator is 6,556 unique current List entries: every record in the supported, non-duplicate National Heritage List for England layers whose source geometry intersects Coventry or one of the five Warwickshire local-authority boundaries. The separate Heritage at Risk population covers 1,084 time-specific observations from sanctioned annual workbooks for 2013 through 2025. That total comes from the frozen workbook ledger because column names, identifiers and available fields change between years.

The profile is designed to demonstrate Search and Facets across all eight Explorer presentation planes: Reader, Graph, Links, Timeline, Type, Resources, Map and Narrative. It also covers the selected-record data card, provenance, durable URL state, accessibility and publication, and shows how an additive YAML-LD extension can give existing OKF front matter stable identity and governed graph meaning without breaking ordinary Markdown consumers.

The controlling artifacts are the human-readable profile, machine-readable profile, mapping proposals, feature-coverage contract, 100 evaluation questions and executable journeys. The beginner chapter explains the process before this report applies it.

Public Entry Points

These are the canonical targets exercised by the publication journey:

• Open the external faithful corpus in OKF Explorer
• Read this report as HTML
• Open the faithful corpus landing page
• Open the tiny assurance fixture
• Open the isolated synthetic supplement
• Inspect the planned immutable release

What Was Evaluated

The Evaluation Foundry asks a narrower question than publication assurance:

If these permitted sources are represented faithfully, which Explorer capabilities and user questions can they support, and where does the source evidence stop?

It produces three deliberately separate products.

An attractive demonstration is not allowed to fill a missing source field. Unknown remains unknown. An association remembered from prior knowledge is a question to test or a reason to follow an official link, not permission to add an unsupported edge.

Scope: What “Everything” Means

“Everything in Coventry and Warwickshire” can refer to historic counties, postal addresses, ceremonial geography or modern administration. This evaluation uses a reproducible spatial definition instead:

1. Pin the full-resolution December 2025 ONS Local Authority District boundary layer.
2. Select Coventry (E08000026) and all five Warwickshire districts: North Warwickshire (E07000218), Nuneaton and Bedworth (E07000219), Rugby (E07000220), Stratford-on-Avon (E07000221) and Warwick (E07000222).
3. Query each supported NHLE source layer with its source geometry and the ArcGIS intersects spatial relation.
4. Retain every matching geography before deduplicating by the source ListEntry identifier. A feature crossing a boundary is one asset with two memberships, not two assets.
5. Record the boundary vintage, source-layer identity, request and observation time so the result can be repeated or challenged.

Annual HAR rows use a different, explicitly labelled rule because the annual workbook—not the optional mapped layer—is their denominator. A row is retained only when a Local Planning Authority, Local Authority, Unitary Authority, District/Borough or County Council field names Coventry or the relevant Warwickshire authority. An explicit Warwickshire county value can be retained at county level without inventing a district. Locality, parish, town and city fields are not authority evidence: in particular, “Warwick Bridge” in Cumbria must not match Warwick District. Applying that fail-closed rule removed 25 false-positive observations for two Cumbria assets from the earlier candidate. Every retained HAR geography edge records the exact workbook field and value and says plainly that it is a reversible text normalization, not a spatial intersection.

The authoritative inputs are the Historic England NHLE FeatureServer and the ONS December 2025 LAD boundary layer. The boundary test uses geometry, not the presence of the word “Warwickshire” in an address.

NHLE Denominator

The pinned source query gives the following denominator. Layers 3, 4 and 5 are alternate polygon-display layers for categories already represented by layers 0, 1 and 2, so they are excluded by identity rather than deduplicated after accidental double ingestion.

Zero is a useful result. It lets the Explorer show a bounded empty state for a World Heritage Site or protected-wreck question rather than implying that the category was forgotten.

Completeness is relative to the pinned source response and boundary vintage. A later Historic England edit or a later ONS boundary release can correctly change the denominator.

Geometry Fidelity And Coordinate Reference System

The acquisition uses the ONS boundary service in its declared British National Grid reference system for the intersection request, but asks ArcGIS to deliver every retained NHLE and mapped HAR feature with outSR=4326. The response spatial reference is checked before the feature is accepted. The resulting record geometry is therefore WGS 84 longitude/latitude (EPSG:4326), and the producer performs no hidden coordinate transformation after delivery.

Esri polygons are encoded as rings rather than ready-made GeoJSON polygons. The producer classifies exterior rings and holes by orientation and containment, assigns each hole to its containing exterior, and emits a MultiPolygon when one source feature has disjoint exterior parts. This preserves the source topology instead of flattening several islands into one invalid polygon. The current faithful corpus contains 6,331 MultiPoint, 510 Polygon and 77 MultiPolygon records; 722 annual observations have no source geometry and remain explicitly unavailable.

A representative point is only a map-navigation aid. A supplied source point takes precedence; otherwise a polygon can use a clearly labelled bounding-box centre. Neither replaces the retained source geometry or proves that the point lies on every part of a complex polygon.

Heritage At Risk: Annual Evidence, Not A Timeless Label

The Heritage at Risk input is the Historic England page of annual Registers and maps and its sanctioned workbooks for 2013–2025. The evaluation uses the annual entries, additions and positive-removals sheets. It does not scrape the interactive register.

Each retained row becomes a time-specific observation or event with:

• workbook year, source URL and file digest;
• source sheet, row number and original field values;
• event kind such as entry, addition or positive removal;
• available condition, vulnerability, trend, ownership, priority and methodology values;
• an exact link to an NHLE asset only when the row supplies a matching List entry number.

The workbooks drift over thirteen editions. A column can be renamed, added, removed or left blank; a category can change terminology; an early row may lack the modern identifier or geometry. The adapter therefore has a year-aware alias table and retains the original header and row address. It does not treat a missing value as “good”, “unchanged” or “not applicable”, and it does not guess identifier joins from similar titles.

The workbook supplies a register year, not a publication day. The normalized record therefore carries register_year, year, temporal_coverage and date_precision: year; it deliberately leaves day-precision catalogue timestamps empty. The Timeline can group the declared year without displaying an invented “1 January” date.

The mapped HAR layer is useful for presentation but is not the completeness denominator: spatial coverage, particularly for conservation areas, is not complete enough to stand in for the annual workbooks. The report consequently requires a per-year reconciliation from workbook input rows to included rows, unmatched rows and exact identifier joins.

The frozen source-provenance ledger records this in-scope annual reconciliation:

These rows are observations from particular annual sheets, not 1,084 unique sites and not a claim about current condition. The inspectable ledger is the source-provenance receipt. Its semantic_sheets[].scope_rows values are explicitly labelled as the broad acquisition prefilter: 1,109 rows. The structured scope_reconciliation then records the 25 locality-only false positives removed by the authoritative geography rule, leaving the 1,084 emitted observations above.

Candidate Results Handoff

The table contains properties of the candidate itself. Deterministic execution, deployment observations, live-link freshness and promotion decisions are separate receipts; they do not become front matter or feature status inside the candidate.

Source and transformation evidence is in the source-provenance receipt; the plane-root receipt binds the control, data, search, semantic and presentation planes separately.

The earlier Pages run 30813485357 and heritage-coventry-warwickshire-20260803 release remain historical observations of the first implementation. They are not current promotion metadata. The old release was mutable at the GitHub platform level and used a lightweight tag, so it is not described as immutable. The new external publication gate requires an annotated tag, GitHub immutable releases and a separately signed envelope.

Capability Findings

The feature-coverage contract records the expected evidence. “Strong source support” means the source has suitable fields; it is not a substitute for the release checks in the previous table.

The One-Hundred-Question Evaluation

The question suite turns the original conversation into 100 reviewable questions. It scores retrieval (35 points), display (25), accessibility (20) and plain, evidence-aware publication quality (20). A score measures Explorer behavior; it is not an assurance score for Historic England data.

Questions The Source Should Answer Directly

• Place and discovery (HQ001–HQ020): find source records for Coventry, Warwick, Rugby, Nuneaton, Bedworth, Stratford-on-Avon and familiar named assets.
• Designation and grade (HQ021–HQ035): combine category, grade and exact boundary facets; distinguish Grade II from Grade II*; explain supported zero-result categories.
• Annual risk evidence (HQ036–HQ055): find what appeared in a particular workbook year, separate entries/additions/removals, show available condition fields and trace a result to its source row.
• Source-backed graph questions (HQ071–HQ079): distinguish exact NHLE boundary intersections, exact HAR-to-NHLE identifier joins and reversible HAR authority-field normalizations, then show the authority/evidence attached to each edge.
• Search and identifiers (HQ081–HQ095): recover declared alternatives and bounded misspellings, search List entry numbers and geography codes, and inspect publisher, geometry, licence and observation evidence.
• Semantics and publication (HQ096–HQ100): explain YAML-LD, distinguish assertion status from assertion scope, prove synthetic isolation and state the publication boundary.

Questions That Need A Qualified Answer

Period and person questions (HQ056–HQ070) deliberately probe prior knowledge: medieval Coventry, Roman Alcester, Shakespeare, Anne Hathaway, Lady Godiva, Basil Spence, Capability Brown, George Eliot and Frank Whittle. The NHLE open layers used here contain names, designation fields and geometry, not the full rich-page narrative or a complete person/period authority file.

The correct responses are therefore one of:

1. return records where the searched words occur in a source title or declared alias;
2. link to the official rich page for fuller evidence;
3. show a bounded empty state; or
4. state that this source cannot support the relationship.

The Explorer must not turn “this building is in Coventry” plus “this person is associated with Coventry” into a person-to-building edge. A future governed source could add that evidence; the isolated synthetic supplement can show how the interface would present it without claiming it is true.

Two representative identifier-bound NHLE rich pages are Historic England’s Cathedral Church of St Michael, Coventry and Warwick Castle. They are representations to inspect, not text ingested into the corpus. For a HAR annual row, the safe live counterpart is instead Historic England's register search for its source List Entry Number. The register's per-result item ID is opaque and is not derivable from the NHLE number, so the producer must not fabricate a /list-entry/{NHLE} path.

Search: Alternatives And Misspellings Without Corrupting Evidence

The index gives each record one official display title and a separate bounded set of search aliases. Aliases can include:

• List entry number forms such as 1342941, NHLE 1342941 and List Entry 1342941;
• source category and grade forms such as Grade I, Grade 1 and Grade One, or Grade II*, Grade II star and Grade 2 star;
• authority names and official geography names/codes;
• reversible punctuation and wording variants such as St/Saint, and/&, and Stratford-on-Avon/Stratford upon Avon;
• source-provided or reviewed familiar names where evidence exists.

Search ordering is deliberate: declared aliases and exact matches win before prefix matches, and typo candidates are considered only after those stronger matches. The static index uses deterministic, bounded one-edit Damerau–Levenshtein correction, covering one insertion, deletion, substitution or adjacent transposition. This is why queries such as Coventtry Cathedral, Warick Castle, Kennilworth Castle and Shakespear Birthplace can be tested without enabling unbounded fuzzy matching.

For a corrected query the interface shows which token changed and why the result matched. It continues to display the source title. Candidate counts, corrected query tokens and index shards are capped so a typo cannot turn into an uncontrolled browser workload. Search variants improve recall; they do not declare that two people, places or concepts are equivalent.

Reviewed discovery names have their own provenance. They do not replace the statutory display title or identifier:

The last example is deliberately not treated as a statutory alternative title for the whole Spa Gardens registration. Each evidence page is also retained as a separately labelled resource, so a reviewer can inspect why the discovery name was admitted.

Beginner’s Guide: What YAML-LD Adds To OKF

OKF Markdown already combines a readable page with YAML front matter:

---
type: Heritage Asset
title: Cathedral Church of St Michael, Coventry
resource: https://historicengland.org.uk/listing/the-list/list-entry/1342941
---

That is useful and remains valid. A person can read it and an existing OKF consumer can display type, title and resource. The limitation is that a field name such as type, and a line joining two local record keys, have only the meaning their application happens to assign.

The suggested extension adds a semantic layer; it does not replace OKF or Markdown. For a beginner, the practical difference is:

This means a conventional OKF reader can continue to render the original fields, while a semantic-aware reader can connect the same identified thing across interface areas and explain why a graph edge exists. No reader has to understand RDF merely to display the Markdown.

The exemplar uses YAML-LD as a local name for an additive extension; it is not a W3C-defined YAML syntax or media type. YAML-LD is the canonical authoring form. A safe YAML parser first accepts a JSON-compatible subset—string-keyed maps, lists and scalar values, UTF-8 text and finite numbers, with no executable tags, cycles or duplicate keys. That is converted to the JSON data model and processed against pinned JSON-LD contexts. The normalized graph and its semantic plane root define semantic identity. In this large generated corpus, the builder first emits deterministic YAML, reparses those exact bytes through the safe YAML 1.2 loader, and derives the semantic shards and JSON-LD from that parsed document. The graph is normalized as URDNA2015 canonical N-Quads, so comments, indentation, key order and scalar quoting do not alter its semantic digest. A separate artifact root continues to bind exact bytes. JSON-LD is then generated as an interchange materialization whenever that semantic plane changes and again for a release; it is not a second hand-edited source. JSON-LD keywords beginning with @ are quoted because plain YAML does not accept them as unquoted keys in every parser.

The ordinary fields stay in place, while semantic consumers can additionally read @context, @id, @type and governed relationship assertions:

---
"@context":
  - https://chris-page-gov.github.io/okf-explorer/profile/bundle-wiki/v1/context.jsonld
  - https://chris-page-gov.github.io/okf-explorer/profile/bundle-wiki/v1/semantic-context.jsonld
"@id": https://historicengland.org.uk/listing/the-list/list-entry/1342941
"@type": https://schema.org/LandmarksOrHistoricalBuildings
type: Heritage Asset
title: Cathedral Church of St Michael, Coventry
resource: https://historicengland.org.uk/listing/the-list/list-entry/1342941
route: asset/1342941
assertion_status: official
assertion_scope: real-world
"https://schema.org/containedInPlace":
  "@id": https://statistics.data.gov.uk/id/statistical-geography/E08000026
---

An older reader can ignore or preserve unknown extension fields and continue to render type, title and resource. A semantic reader compiles the final property into the direct statement “this asset is contained in Coventry”; the separate reified assertion supplies its boundary-intersection evidence, authority, derivation and rights.

1. Stable Identity

@id states that the Markdown page, search row, map feature, graph node and source representation concern the same entity. It avoids identity based only on a mutable title or a local file name.

2. Governed Types And Predicates

@type and predicate IRIs point to published meanings. A predicate registry can give each relationship a preferred label, inverse label, domain, range, source vocabulary and evidence rule. The Graph can therefore show “located in” from asset to geography and “contains” in the other direction while the data card explains the same edge.

3. An Integrity-Bound IRI-To-Route Registry

An IRI is a global identifier; an Explorer route is a local navigation target. The extension publishes a registry that maps one to the other and binds it by SHA-256 digest. The UI opens a safe internal route only when the entity is in the registry. It does not guess a path by stripping text from an external URL. External evidence remains an external link.

4. A Direct Assertion Plus Its Evidence Record

RDF reification describes a statement but does not itself make the underlying statement true. The exemplar therefore emits both:

asset ── containedInPlace ──> geography       direct assertion
  └── authority, evidence, derivation,
      date, rights, confidence and scope      reified assertion metadata

Validation requires one direct triple and one matching reified rdf:Statement/okf:RelationshipAssertion. Legacy graph consumers still see the direct edge; semantic consumers can inspect why it exists.

5. Authority And Reality Stay Separate

Two labels answer two different questions:

An exact NHLE boundary membership is a normalized real-world assertion: Historic England supplies the asset geometry, ONS supplies the boundary and the evaluation performs the declared intersection. A HAR geography relationship has a different, deliberately reversible basis: it records the accepted local-government workbook field and original value, then applies the published authority-name mapping. It is also normalized real-world evidence, but it is not called a spatial intersection. A HAR-to-NHLE relationship is made only when the workbook gives the exact List entry identifier. A hand-authored fictional person edge can be carefully modelled but remains synthetic-fixture.

6. Linked Interface Experiences

The semantic identity is useful across the interface, not only in an exported graph:

• Search can open the registered record route while retaining the official source IRI.
• The Type plane can group a published semantic class without hiding source-native categories.
• Graph edge selection can show predicate meaning, inverse wording, authority, derivation, evidence and assertion scope.
• The map and timeline can project the same identified records as the current query and facets.
• Resources can distinguish an internal entity route, frozen machine-readable evidence, an NHLE rich page and an exact HAR register search.
• The selected-record card can show both human-readable fields and semantic identifiers without asking a beginner to read raw RDF.

7. Machine-Checkable Meaning

Local copies of the contexts, predicate registry and IRI-route registry are pinned by digest. A change to a term or route changes the URDNA2015 normalized graph digest and semantic plane root, then reruns only the checks that depend on it. Formatting-only YAML-LD changes leave that semantic root stable while the exact-byte artifact root changes. This separates semantic drift from editorial diffs without hiding either one.

The generated YAML-LD graph, JSON-LD interchange, semantic validation report, IRI-to-route registry and predicate registry make those claims inspectable rather than leaving the proposal only in prose.

YAML-LD does not make a claim true, choose the right ontology, grant rights to copy a rich page, prove completeness or make an interface accessible. Sources, mappings, validation, domain review and consumer testing still do that work. The proposal is compatible with the JSON-LD 1.1 model and the explanation of RDF statements and reification, but it is presented as a suggested extension beyond the current permissive OKF core.

Rich Pages, Resources And Link Validation

The open-data record and the rich HTML page serve different purposes. The FeatureServer supports systematic acquisition of identifiers, category, grade, dates and geometry. The rich page is the official place for fuller description and legal context. The evaluation links to it but does not bulk copy it.

For every NHLE record the producer:

1. accepts only an HTTP(S) URL without embedded credentials;
2. permits the Historic England origin for the primary rich page;
3. requires the final /list-entry/{number} segment to match that record’s ListEntry;
4. constructs the canonical identifier-bound URL when a declared source link is absent or unsuitable;
5. records the exact machine-readable query and frozen evidence separately.

For every annual HAR record, the frozen workbook row remains the time-specific authority. Where it supplies a numeric List Entry Number, the producer links to the current official results endpoint with exactly q={number}. Historic England's old /search-register/list-entry/{NHLE} pattern returns a 404 and the current result's opaque item ID cannot be inferred safely. Deprecated fixture URLs are therefore normalized to the exact search; credentials, extra query parameters, fragments and lookalike origins fail closed.

Link assurance has five distinct gates:

A live URL can change after the observation time. Cloudflare can also make a generic unattended HTTP client a poor proxy for a user browser. Identifier binding is therefore exhaustive, while external availability is refreshed on its own schedule. Historic England pages that challenge fresh automated contexts are opened in a genuine interactive browser. The resulting receipt records requested and final URLs, HTTP status, title, bounded identity text and observation time outside the candidate. Its digest can be included in a signed promotion envelope. A challenge page, HTTP 403, unexpected redirect or missing identity remains a failed genuine-browser observation.

The bulk channel deduplicates the generated occurrences into canonical URL intents and refreshes them on a bounded hash-shard schedule. Terminal assurance uses the publication manifest to read every rendered HTML page, extracts every external anchor, then unions those URLs with the independently verified faithful, tiny and synthetic link-intent manifests. The receipt binds the publication-manifest digest, all three intent-manifest digests and roots, the rendered-anchor root, the protected journey and the final canonical-URL root. At promotion the checker reconstructs that same union from R1 bytes: an omitted anchor, omitted fixture universe, extra receipt URL or changed source root fails closed. In beginner terms, there is no hand-written list that can quietly fall behind the Site; the list to check is derived from everything actually published.

The present closure is below a reviewed 14,000-URL ceiling. Forty-eight bounded workers, a six-second request timeout and at most two attempts per URL give a nominal worst-case network budget below 59 minutes. A 75-minute outer timeout leaves 105 minutes of the 180-minute job for genuine Chrome and the three-engine journey. Crossing the URL ceiling or either timeout fails the terminal gate and requires an explicit policy review; it cannot silently publish partial evidence. Historic England returns HTTP 403 for many identifier-bound official record and resource URLs even when their exact host and identifier contracts have already passed. The versioned policy may classify only that exact combination—host historicengland.org.uk, risk official-record or official-resource, and status 403—as protected-origin, with the named validation basis candidate-identifier-binding-plus-protected-origin-http-403. This records an origin-protection outcome, not live page availability or identity. A different host, subdomain, risk, status, missing basis, or unexpected final host still fails, as do unpublished Site resources returning 404. Representative rich pages continue through the genuine-browser gate above. Because intents are hash-sharded, an expired or changed URL refreshes its observation and affected shard without rebuilding unrelated data, search, semantic or presentation planes. A successful link check does not expand the page’s licence or authorize copying its text. The machine-readable data attribution remains subject to the source terms and the Open Government Licence v3.0.

Deterministic Assurance

The tiny fixture is exactly three source-backed records selected from the frozen full snapshot: two NHLE assets and one 2025 HAR observation. It is a fast gate for the same producer, never the denominator or main population. Boundary geometry was used during source acquisition; the fixture retains record identities and canonical geometry digests but omits the large local-authority boundary coordinate arrays. It still exercises exact, alias and misspelled search, facets, point and polygon asset geometry, rich and machine-readable resources, qualified relationships, a timeline bucket and the selected-record card.

For a fixed snapshot and generation timestamp, assurance requires:

1. schema and source-contract validation before mapping;
2. two independent builds with byte-identical files;
3. unique record, resource, route and assertion identities;
4. every manifest path confined to its publication root;
5. content digests for chunks, search shards, contexts and registries;
6. separate roots for control, data, search, semantic and presentation planes, with a fail-closed impact plan selecting the affected closure;
7. exact denominator reconciliation;
8. negative fixtures that reject duplicate IDs, unsafe paths or URLs, bad digests, unmatched semantic assertions and synthetic leakage;
9. execution in the real Explorer, not only producer-unit tests.

The full journey starts with a familiar title, repeats with a formal name and a one-edit misspelling, applies the Coventry local-authority facet, and carries that same state through Reader, Graph, Links, Timeline, Type, Resources, Map and Narrative. It applies a Map filter, selects an edge and map record, hydrates a full record, opens an official link in a new tab, then proves Back, Forward and reload preserve the intended state.

The publication journey separately checks the generated index, methodology, profile, beginner chapter and this report as HTML pages. Before it starts, the evaluator compares both the deployed descriptor SHA-256 and deployed plane-root digest with the candidate receipt; a stable descriptor cannot disguise an older executable closure. A failed deployed URL is reported as unverified. It is not silently converted into a rebuild with the same release identity, and a success is written to the signed envelope rather than back into the candidate.

Synthetic Capability Supplement

The synthetic supplement contains an invented place, person and proposed future event so the interface can show typed people, uncertainty and proposed relationships that the faithful source cannot establish. Its descriptor and front matter declare:

assertion_scope: synthetic-fixture
default_loaded: false
include_in_counts: false
include_in_search: false

It has its own base namespace, routes, index, graph and plane roots. The faithful descriptor does not import it. The isolation journey loads it only by its explicit descriptor and checks the visible synthetic warning. A synthetic example can demonstrate an interface possibility, but it cannot improve a faithful coverage score or answer a real-world question.

Honest Gaps And Limits

• This is a snapshot. Current designation and risk status must still be checked with Historic England.
• The boundary is a chosen modern definition. It does not claim to model the historic or ceremonial county of Warwickshire.
• NHLE intersection is not containment. A crossing feature retains every intersected geography; the UI wording must not imply that its whole geometry lies inside one district.
• HAR geography has a different evidence rule. It is a reversible mapping from an accepted authority field and value, not a geometric intersection; locality, parish, town and city text is not sufficient scope evidence.
• Geometry delivery is WGS 84. Accepted ArcGIS feature responses declare EPSG:4326; the producer normalizes Esri ring structure, including holes and disjoint MultiPolygon exteriors, but does not transform the coordinates.
• Representative points are schematic. Full source geometry remains the evidence for polygon shape and location.
• NHLE open fields are not the whole List entry. Detailed periods, people, descriptions and legal text may exist only on a linked rich page.
• HAR is annual and schema-changing. A missing field is unknown, an old observation is not automatically current, and a workbook year is not an invented day-precision publication date.
• Exact identifier joins are intentionally conservative. Unmatched HAR rows remain unmatched instead of being joined by title similarity.
• Search tolerance is bounded. It catches declared alternatives and a single edit; it is not a semantic search engine and may correctly leave a broader prior-knowledge query unanswered.
• Provenance is not independent audit. It shows who said what, when, and how a normalization was made.
• Link availability and rights differ. A working page can later move, and open machine-readable data terms do not automatically apply to all rich-page text or imagery.
• Automated accessibility is incomplete. Keyboard and programmatic checks require complementary review with assistive-technology users.
• Evaluation is not certification. Passing the profile demonstrates functionality over its stated inputs; it does not create a new assured heritage register.

Promotion Decision Gate

A candidate is eligible for promotion only when all of these conditions are met for its exact digests:

• the emitted NHLE asset count reconciles exactly to 6,556;
• the 2013–2025 HAR ledger reports every workbook/sheet input, in-scope output, unknown and unmatched identifier without hidden loss;
• every candidate-results value above is evidence-backed and every required observation receipt exists outside the candidate;
• the tiny, faithful and synthetic descriptors validate and remain isolated;
• all deterministic, schema, semantic, search, geospatial and component Site checks pass for the impact-plan closure;
• all 100 questions have a result, a bounded empty state or an explicit source gap rather than an invented answer;
• the real Explorer journey passes with one coherent query/facet state; and
• the exact external GitHub Pages HTML and bundle URLs pass real-browser identity, rendering and link checks;
• the annotated release tag resolves to the intended commit and GitHub reports the release immutable; and
• a signed promotion envelope binds the candidate, observations, deployment and release identity without modifying any candidate byte.

Only the signed envelope may state the resulting promotion status. This report does not pre-announce that decision. Even a successful promotion does not turn the evaluation into a legal register, condition survey or certification. Historic England remains the authority for the National Heritage List for England and Heritage at Risk.