LICENSES.md

Licences

This dataset is a collection of 1,691 separately licensed photographs, not a single relicensed work. Each row keeps the licence it arrived with, recorded in its own license, license_spdx and license_url columns. Nothing here relicenses any photograph, and the repository-level licence tag is metadata rather than a grant.

Inventory

Licence	SPDX	Files	Deed
CC BY-SA 4.0	CC-BY-SA-4.0	896	https://creativecommons.org/licenses/by-sa/4.0/
CC BY-SA 3.0	CC-BY-SA-3.0	668	https://creativecommons.org/licenses/by-sa/3.0/
Public domain	—	52	https://creativecommons.org/publicdomain/mark/1.0/
CC BY 4.0	CC-BY-4.0	21	https://creativecommons.org/licenses/by/4.0/
CC BY 3.0	CC-BY-3.0	19	https://creativecommons.org/licenses/by/3.0/
CC BY 2.0	CC-BY-2.0	15	https://creativecommons.org/licenses/by/2.0/
CC BY-SA 3.0 pl	CC-BY-SA-3.0-PL	9	https://creativecommons.org/licenses/by-sa/3.0/pl/
CC0	CC0-1.0	7	https://creativecommons.org/publicdomain/zero/1.0/
CC BY-SA 2.0	CC-BY-SA-2.0	3	https://creativecommons.org/licenses/by-sa/2.0/
CC BY-SA 2.5	CC-BY-SA-2.5	1	https://creativecommons.org/licenses/by-sa/2.5/

Modification

1,538 of the 1,691 files are modified: they were downscaled to at most 2000 px on the long edge and re-encoded; EXIF not preserved. The remaining 153 are byte-identical to the Commons original. The modified column says which, and it is derived by comparing the stored bytes against the Commons digest in commons_sha1 rather than asserted — so you can check it rather than trust it.

Public-domain files

Files recorded as Public domain carry the Creative Commons Public Domain Mark, which is a label rather than a licence: it asserts freedom from known copyright without saying on what basis. The license_template column carries the Commons template naming that basis where it could be retrieved.

What you must do

• Attribute each photograph to its own photographer. The attribution_text column is a ready-to-paste credit line; credits.csv carries all of them.
• Keep the licence with the row. If you redistribute a subset, filter credits.csv to it and ship that too.
• Say the files are modified where modified is true. They are adaptations.
• ShareAlike binds your adaptations, not this collection. If you crop, augment or composite a CC BY-SA photograph, release the result under that photograph's own licence version. Because this collection spans CC BY-SA 2.0 to 4.0, an arbitrary slice inherits a mix of obligations — filter by license_spdx first if you need a single-licence derivative.
• Add no further restrictions. No terms are imposed here and none may be added.