Methodology
Source before certainty.
How the pre-launch product is designed to preserve source facts, show limits, handle changes and avoid turning directory data into medical recommendations.
Source version: MHLW Medical Information Net open-data snapshot dated 1 June 2026, processed into a versioned 47-prefecture package. Public redistribution and final attribution still require qualified source-rights review.
Acquisition
Inputs are bound to official archive URLs, hashes, a snapshot date and a processing version. Source files are not silently replaced by later downloads.
Transformation
Normalization and sharding are deterministic and preserve provenance. Controlled English/Japanese aliases map only to exact official municipality or department code/name pairs and never overwrite the canonical source value.
Neutral display
Provider order must remain factual and neutral. The product does not score quality, popularity, medical fit or likelihood of access. Payment, claiming and Clinic Services cannot alter organic order.
Changing facts
Hours, contact, address, language support, accessibility, insurance, payment, availability, booking and emergency capability need the required current field-level evidence. Unknown, stale, disputed or suppressed fields fail closed rather than borrowing certainty from another field.
Corrections
The official source layer remains immutable. A correction or provider evidence becomes a separate, versioned overlay with authority, date, expiry, dispute and audit state. Claiming is not verification and a verified field is not a verified provider.
Confirm before relying
MHLW warns that provider-reported information can be outdated or contain errors. Confirm consequential or time-sensitive details with the current authoritative source or provider. No listing establishes current availability, emergency capability, language support, insurance acceptance, price or suitability.