Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file must have an additional copyright tag indicating the copyright status in the source country. Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:US519333-Window_frame_with_sash_(1).jpg
In specific cases, patent applicants and holders may claim copyright in portions of those documents. In those specific cases, applicants are required to identify the portions that are protected under copyright, and are additionally required to state the following within the body of the application and patent (see 37 CFR 1.71(d) & (e) and 37 CFR 1.84(s), and MPEP § 608.01(e) & (w) and MPEP § 1512):
A portion of the disclosure of this patent document contains material which is subject to (copyright or mask work) protection. The (copyright or mask work) owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all (copyright or mask work) rights whatsoever.
The original patent should be checked for the presence of such language before an assumption is made that the contents are in the public domain. (This template can be replaced by {{PD-US-patent-no notice}} in such cases.)