Works that are in the public domain in the United States cannot be registered with the U.S. Copyright Office. A copyrighted work enters the public domain in the United States when “its full copyright term has expired.”
Works that do not comply with certain statutory formalities may also be in the public domain, such as U.S. works published without a copyright notice on or before March 1, 1989, or U.S. works published or registered on or before December 31, 1963 that were not renewed in a timely manner. Likewise, works that are not copyrightable are in the public domain, such as works that have not been fixed in a tangible medium of expression or works that merely contain a de minimis amount of authorship.
A derivative work, compilation, or collective work that contains public domain material may be registered, provided that the new work contains a sufficient amount of original authorship. The copyright in such works covers the compilation authorship or the new material that the author contributed to the derivative work, the compilation, or the collective work, but it “is independent of, and does not affect or enlarge the scope, duration, ownership, or subsistence of, any copyright protection in the public domain material.”
Pornographic works may be registered with the U.S. Copyright Office, provided that they contain a sufficient amount of original authorship. As a general rule, a registration specialist will not examine a work or authorship to determine whether it contains material that might be considered obscene. If the Associate Register determines that the work clearly falls within the scope of Title 18, sections 2251-2255, and if the Register of Copyrights concurs, the application, deposit copy(ies), and any other materials that have been submitted to the Office will be referred to the U.S. Department of Justice.
If the U.S. Copyright Office is aware that the deposit copy(ies) contain information that has been classified by the U.S. government, the registration specialist will refer the work to the Associate Register of Copyrights and Director of Registration Policy & Practice. The material should be held or disposed of in accordance with instructions from the Associate Register, and the examination or other processing of the material by the Office should be suspended until the matter has been resolved.