MediaWiki:UploadFormLicenseHelp

License: The Commons accepts only media that either

• are explicitly licensed under a free license such as the GFDL, the Creative Commons licenses {{Cc-by-4.0}} or {{Cc-by-sa-4.0}}, or similar free licenses, or
• are in the public domain both in the U.S. and in the source country of the work.

The most common license and copyright status descriptions are listed in this drop-down menu. Choose the one that applies to your file, if you haven't already placed a copyright tag in the "Permission" field above. See also Commons:Licensing.