摘要

Source

许可协议

	此作品在美国属于公有领域，因为其是由美国政府的官员或雇员，基于其个人公务目的制作的作品，参考美国法典第17篇第1章第105条。 注意︰本模板仅适用于美国联邦政府的原创作品，不适用于任何美国州、属地、联邦个体、县、市或任何次级政府的作品。本模板也不适用于1978年以后由美国邮政署出版的邮票图案（参看美国版权局实践纲领第313.6(C)(1)条）。也不适用于部分美国硬币；参看美国铸币局使用条款。
本文件已被确认为免除已知的著作权法限制（包括所有相关权利）。

https://creativecommons.org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse

...However, any copyright held by ACME that is still current would now be owned by CORBIS. In an attempt to determine if ACME registered any copyrights and if those copyrights were renewed, Specialists in the Prints and Photographs Division of the Library of Congress searched the Copyright Office files. It was found that only a few images were registered for copyright and those copyrights were not renewed. However, the Library’s legal office has advised the Division that photographs published with proper copyright notices between 1923-1963 may be protected if properly renewed, while works published after 1963 and unpublished photographs in the collection may be protected even if they were not registered with the Copyright Office. Additionally, researchers should be advised that determining the copyright status of photographs can be problematic because of the lack of pertinent information, and researchers often have to make calculated risk decisions concerning the appropriate use of an image when its copyright status is unknown or ambiguous.

— https://www.loc.gov/rr/print/res/220_acme.html