In all cases the uploader must provide appropriate evidence to demonstrate either that the file is in the public domain or that the copyright owner has released it under a suitable licence. Typically that requires at least that the source of the file be specified, along with the original source where the file is a derivative work. Also, the creator or copyright owner should be identified, if known or reasonably ascertainable. If there is any question, evidence may need to be supplied that the copyright owner has indeed released the file under the given licence.
Where the file is a photograph which shows an identifiable person, the subject's consent may be required as described at Commons:Photographs of identifiable people.
In all cases, the burden of proof lies on the uploader or other person arguing for the file to be retained to demonstrate that as far as can reasonably be determined:
- the file is in the public domain or is properly licensed, and
- that any required consent has been obtained.
- Note that in the case of files found on the Web, this should not be the URL of the file, but the URL of the page containing the file, so that Commons editors can find background information when required.