File:Kerkhoffs.jpg

To use this template, the image must meet both of the following two conditions:

1. published over 70 years ago, and
2. the original author's actual identity was not publicly disclosed in connection with this image within 70 years following its publication.

Images that lack either of these two conditions should not use this template.

Reasonable evidence must be presented that the author's name (e.g., the original photographer, portrait painter) was not published with a claim of copyright in conjunction with the image within 70 years of its original publication. Works which had not entered Public Domain in their country in 1996 that were uploaded before 1 March 2012 should be marked additionally with {{Not-PD-US-URAA}}.

Note: In some countries anonymous works are copyrighted until 70 years after the death of the author if the author's identity became public in any way during the original term. In Germany this applies to certain works published before July 1, 1995; see Übergangsrecht.

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:Kerkhoffs.jpg