india_pincode_directory.csv — provenance and licence

Source: GeoNames postal code dataset for India,
  https://download.geonames.org/export/zip/IN.zip
  (155,570 post-office rows, fetched 2026-08-16)

Licence: Creative Commons Attribution 4.0 International (CC BY 4.0)
  https://creativecommons.org/licenses/by/4.0/
Attribution: This product includes postal code data from GeoNames
  (https://www.geonames.org/), licensed under CC BY 4.0.

Transformation: compacted to one row per unique 6-digit PIN
  (19,238 rows). Each row carries a representative locality and the
  modal district/state across that PIN's post offices. Columns:
  pin, locality, district, state. Lines starting with '#' are
  comments.

This is geographic reference data, not clinical data: it makes no
claim a doctor must verify. It exists so patient registration can
suggest "district, state" from a typed PIN without any network call
and without any patient detail leaving the device.
