For many creators, educators and consumers, copyright can be an incredibly complicated subject matter, with seemingly simple phrases like “fair use” and “public domain” offering more questions than answers. Earlier this year, we posted answers to a number of our most frequently asked questions about Copyright, including how to register a copyright and how to obtain permission to use copyrighted work.
One area not covered in depth in that compilation was public domain. The phrase “public domain” is one that is often discussed in the context of copyright, but it is not often defined or explained in an understandable way. This is an especially important topic, as a lack of understanding about what is, and is not, included in the “public domain” can lead to infringement, whether or not it was intended.
In the simplest terms, public domain refers to items that cannot be protected by copyright, or whose copyright protections have expired.
According to the Copyright Act, items which cannot be protected by copyright include:
“…any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work.”
This means you could copyright a book you authored that describes, explains and illustrates a scientific discovery, but you cannot receive copyright protection for the discovery itself. Granting copyright protection to a discovery – or an idea, concept or process – would effectively monopolize and restrict access to, and use of, that discovery, and defeat the purpose of copyright as stated in the Constitution: to encourage the progress of science and art.
In addition to items that cannot be copyrighted, the term public domain also includes original works of authorship once their copyright has expired. Under current copyright terms, any work published/copyrighted prior to 1923 is now in the public domain. For works copyrighted after 1923, one must conduct a search through the U.S. Copyright Office to determine if the work has entered the public domain or if it is still protected by copyright.
Once a work enters the public domain, it is no longer protected by copyright and can be used by anyone without permission or license.