
If an image is only available at a low resolution, the user may have original-resolution photos on their local disk, so in addition to uploading a low-resolution version, contact them to ask if they can send you higher-resolution photos.If the user has disabled commenting, consider sending them a message via FlickrMail instead. It would be polite and collegial to leave a comment on the image's Flickr page stating that it was uploaded to Commons.

Flinfo can also handle static Flickr URLs. Input the image ID, or the full URL of a Flickr image.

CC-BY to CC-BY-SA), Commons is not required to match this as the freer license is not revocable.

As above, however, if the Flickr user changes the license to a less-free version (e.g. Flickr allows its users to select the license of their choice and to change it at any time, but it is easy to verify that a photograph was freely licensed in the past as Flickr now shows license history as of October 25, 2022.
