Description of need: In essentially all use cases I can think of where someone wants to filter for media with a specific license (e.g. looking for photos they can use for something they are making) any photo with a more permissive license would also work. Someone looking for photos to use for some non-commercial field guide, for instance, would be fine to use each of CC-0, CC-BY, or CC-BY-NC photos, but having to always look through each of these individually is a pain.
Feature request details:
On the photo browser page, rather than filtering for photos with exactly the license selected, also include any photos with more permissive licenses. So e.g. selecting “CC-BY-NC” would also include any photos with CC-0 or CC-BY.
Caveat: filtering to CC-BY-NC-SA should not include CC-BY-SA photos as these licenses are mutually incompatible.
If anyone has a non-niche use case that this would cause problems for please let me know as I can not think of any!
I can think of one important counterexample. Wikipedia accepts CC-0, CC-BY, and CC-BY-SA, but not CC-BY-NC. In other words, to search for all photos with a Wikipedia-compatible license, add the following parameter to the search string: &photo_license=cc0,cc-by,cc-by-sa
The request is to only include strictly more permissive licenses. So not only is that not a counterexample, it’s actually something that would be easier in this system. Filtering to CC-BY-SA (as one would do for searching for photos for wikipedia) would return all and only those observations licensed more permissively, i.e. as CC-0, CC-BY, CC-BY-SA, which are exactly those licenses usable on Wikipedia. CC-BY-NC and CC-BY-SA are incomparable in permissiveness, both include restrictions the other does not (non-commercial and share-alike, respectively), so filtering for one would not return images licensed under the other under my proposal.
Explicitly, filtering for…
CC-0 would return CC-0 photos
CC-BY would return CC-0 and CC-BY photos
CC-BY-SA would return CC-0, CC-BY, and CC-BY-SA photos
CC-BY-NC would return CC-0, CC-BY, and CC-BY-NC photos
CC-BY-NC-SA would return CC-0, CC-BY, CC-BY-NC-SA photos
Yes, I understand now, thanks for explaining. However, the “algebra of licenses” is not intuitive. No one will understand how to use this feature without consulting the documentation.