Thailand Canonical Administrative-Names Reference

A canonical reference dataset for Thailand's administrative divisions at all three levels: 77 provinces (ADM1), 928 districts (ADM2), and 7,436 subdistricts (ADM3). Each row carries cross-system identifiers (TIS-1099, ISO 3166-2, HASC, FIPS, Wikidata Q-ID, GeoNames ID, OSM relation ID, Wikipedia URL), normalized English and Thai names, computed geographic columns (centroids, areas, bounding boxes, distances, international borders, coastline lengths), and operational lookups (postal-code prefixes, telephone area codes, district and subdistrict counts).
The artifact composites four MIT-licensed upstream Thai-province repositories with explicit override rules, an audit-trailed override registry (one founding entry: Lopburi / Loburi), a historical-mappings registry (Bueng Kan / Nong Khai 2011 split), and a verified-establishment-year registry. Bundled GeoJSON polygons at all three administrative levels accompany the tabular outputs.
Validation discipline: 36 schema-and-consistency checks, 49 cross-level integrity checks, 54 mutation tests proving the validator catches deliberate errors, and three Wikipedia-attested verification reports (infobox area + centroid cross-check, alternates attestation, upstream drift detection). The full build pipeline reproduces byte-identically from cached upstream inputs via a single orchestrator script.
License: Creative Commons Attribution 4.0 International (CC BY 4.0) on the data tables and the methodology document; MIT on the build code and validator; layered upstream licenses on bundled polygon files (per-file documentation in NOTICE.md).