# 260614 — Wikibase / Wikidata deep dive

Deep dive on **Wikibase** (the MediaWiki extension behind **Wikidata**) as the
**entity-statement (RDF) far end** of the structure and native-query spectra: items and
properties, statements = claim + qualifiers + references + rank, stable opaque IDs, and
**SPARQL** (Wikidata Query Service / Blazegraph) including **federated** queries.

- `findings.md` — data model, RDF/SPARQL surface, storage & history, capability profile,
  INTENT mapping, UC seeds (UC-73–UC-75), architecture notes for SHARD-WP-0002, open
  questions, sources, traceability.

Catalog yield: UC-73 (attach a typed entity-statement / RDF shard, lossy render to a page),
UC-74 (graph query the union via SPARQL + federated `SERVICE` cross-endpoint query), UC-75
(statement-level provenance — references + rank per assertion). Enriched UC-34/58/52/24.
Feeds SHARD-WP-0002 T12 (structured/typed page model) and T16 (stable language-neutral
identity ≠ label/placement).