Works in the Public Domain are outside the protection of copyright law. They may be freely used without permission. Works may have entered the public domain in a variety of ways, due to changes in copyright law over time.
- Their copyright protection has expired. Works published in and before 1928 (as of 01/01/24) in the United States are now in the public domain. See Public Domain Day 2024).
- The copyright owners was required to renew the copyright and failed to do so. This is no longer required for works created after 1978.
- The copyright owner explicitly places the work in the public domain.
- Copyright law does not protect the type of work. Titles of books or movies cannot be copyrighted, lists of ingredients, facts, and ideas. Any work created by a U.S. government employee or officer is in the public domain, provided that the work is created in that person's official capacity (17 USC 105).
Best practices dictate that public domain works be properly attributed. It is still possible to plagiarize public domain works.
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