jpmapdata copyright and data notices

Package-specific documentation and helper code:
Copyright (C) 2026 Yusaku Horiuchi.

Bundled boundary data
---------------------

inst/extdata/jpmap_boundaries_2024_47.gpkg

This GeoPackage contains official MLIT N03 2024 administrative area data for
Okinawa Prefecture, converted by jpmap to GeoPackage format and standardized for
package examples. Source: Ministry of Land, Infrastructure, Transport and
Tourism (MLIT), National Land Numerical Information, N03 Administrative Area
Data, 2024.

Source page:
https://nlftp.mlit.go.jp/ksj/gml/datalist/KsjTmplt-N03-2024.html

MLIT terms page:
https://nlftp.mlit.go.jp/ksj/other/agreement.html

The source page lists the 2024 N03 administrative area data as open data
(CC BY 4.0). MLIT requests source attribution and, when content is edited or
processed, a statement that the derived content was created from the source
data.


inst/extdata/jpmap_boundaries_2021.gpkg

This GeoPackage contains a prefecture example layer derived from Natural Earth
1:10m Admin 1 States/Provinces data and an Okinawa municipality example layer
derived from Geoshape historical administrative boundary data.

Natural Earth source:
https://www.naturalearthdata.com/downloads/10m-cultural-vectors/10m-admin-1-states-provinces/

Natural Earth terms:
https://www.naturalearthdata.com/about/terms-of-use/

Natural Earth states that its raster and vector map data are in the public
domain.

Geoshape source:
https://geoshape.ex.nii.ac.jp/city/

Geoshape states that its website content is provided under CC BY 4.0 and
requests the credit:
"Historical Administrative Boundary Dataset beta version" (CODH), doi:10.20676/00000447.
Geoshape also notes that users should consult MLIT National Land Numerical
Information terms for the N03 administrative area data used by Geoshape.