This is an implementation profile, not a blanket certification. English remains the default at /; French lives at /fr/. The separate language-improvement backlog is deferred.
The About-page dataset list is generated from resource frontmatter in i18n/en/resources/*.md. Each record contains English and French titles/descriptions and one shared source identity. Corresponding French Markdown pages provide translated editorial content. Project areas remain ordinary pages and are not exported as datasets.
/catalogue.jsonld is generated during the production build and served dynamically during development. It uses DCAT 3, JSON-LD 1.1, Dublin Core, PROV and SPDX terms. Dataset, distribution, and catalogue-record identities are stable HTTPS fragment identifiers under each English landing page. Resource ids must not change when a title or translation changes. Preserve redirects if a landing path must move.
Exported properties cover multilingual descriptions, spatial coverage, landing pages, pinned distributions, source revisions, checksums, licensing qualifications and metadata review dates. Unknown dataset publishers and issue dates are omitted. Repository commit dates are not represented as dataset publication dates. This is a small DCAT profile; it does not claim DCAT-AP conformance.
Both initial records cite the exact source revision and license evidence. MIT is a repository-declared license, not independent clearance of third-party material. The visible records and JSON-LD retain this distinction. The source MIT notice is retained at /notices/geography-MIT.txt for the derived region inventories. Unknown licensing must use licenseStatus: unknown without a license URL or identifier.
The record's checked date is the metadata review date. Git pull requests preserve the history of changes to catalogue records; the source revision and SHA-256 identify the upstream bytes. Upstream attribution is not replaced by site ownership. Resource ids represent the ongoing catalogue identity; the pinned distribution is the reviewed snapshot.
Each content page receives one absolute self-referencing canonical URL and matching per-page Open Graph URL, title and description. French canonicals point to French pages, not English ones. Directory index routes preserve their trailing slash; other content routes use clean URLs. The 404 is excluded from canonical generation and marked noindex.
Production host redirection and HTTP response headers must still be verified after deployment. The build cannot configure domain redirects.
pnpm check:geography <file.geojson> runs structural checks informed by RFC 7946: geometry types, finite positions, coordinate bounds, feature members, ring closure, basic bounding-box validity and supported CRS interpretation. Null feature geometries are accepted. Antimeridian bounding boxes are supported. Ring winding differences are warnings for backward compatibility. Known legacy CRS84 declarations are disclosed; other legacy CRS values are rejected rather than silently reinterpreted.
pnpm check:sources verifies the exported pinned downloads, checksums and geometry with network access, after building. It fails on unavailable or changed sources and structural errors; warnings are reported. Normal PR checks remain deterministic and do not depend on external services.
Initial review (2026-09-07): US 271 features / 952,249 positions, no structural errors, 48 warnings (47 ring orientations and one legacy CRS84 member). California 147 features / 349,799 positions, no structural errors, 220 ring-orientation warnings. The source snapshots were not rewritten. Coordinate plausibility is not proof of geodetic accuracy, topology, legal boundaries, completeness, or full RFC conformance. Ring-direction checks do not resolve antimeridian polygon topology.
Target: WCAG 2.2 AA. Implemented: static region inventories available without JavaScript; descriptive resource links and headings; semantic rights/details lists; a map skip link; announced map errors and validation warnings; visible keyboard focus; reduced-motion handling; and darker light-theme / lighter dark-theme hero gradients for readable large text.
The catalogue and resource pages are server-rendered. Map overlays are not the sole route to source information. Text inventories identify source features; they do not reproduce a spatial analysis or all boundary geometry. Before claiming AA conformance, perform a full keyboard/screen-reader, zoom/reflow, control-name and contrast audit across both languages. Existing untranslated accessibility labels remain in the explicitly deferred language backlog.
pnpm check runs content parity, focused standards regression tests, the production build and generated-output checks. Tests cover duplicate records, unknown rights, pinned revisions, URL identities, invalid geometries, null features, antimeridian bounding boxes and legacy CRS behavior. Output checks cover internal assets/links, one canonical and matching sharing URL per page, and resolvable catalogue landing pages.
Browser verification on 2026-09-07 confirmed individual page canonicals after navigation, visible skip-to-content focus, corrected map bypass focus, and no horizontal overflow on the California resource page at 320 CSS pixels. Sampled gradient contrast is at least 6.62:1 on white and 9.22:1 on the default dark background; this is not a complete page contrast audit. Both remote source checksum/structure checks passed with the documented warnings.