In this article, we’ll discuss 10 of the most common questions associated with the public domain. We’ll address what is the public domain, how a work becomes part of the public domain, differences between the public domain and forms of intellectual property, how to make profit off of works in the public domain, and some other common questions. In short, the public domain is any information that is accessible to all – for free!

Next, we’ll go over public domain questions 1 through 3.

The public domain represents any creative work, such as a book, writing, photograph, music, etc. that is not protected by law and can be freely used by everyone for any legal reason. In essence, a work in the "public domain" is "public property" for all. NOTE: Many works that fall into the public domain used to be protected by copyright law but now no longer have such protections.

To answer this question you need to know the definitions of the public domain and the intellectual property concepts of a copyright, trademark, and patent. Please refer to Question 1 for the definition of public domain – and remember, a work in the public domain no longer has any legal protections.

A copyright is a legal concept that protects works of authorship (e.g. such as short stories, books, music, plays, choreographies, architectures, movies, etc.) that are fixed in some kind of tangible medium of expression (e.g. on paper, on a recording device, in any kind of fixed material). But a copyright does not protect the actual ideas, procedures, processes, systems, or discoveries in the copyright. For example, if you write a song about love, you cannot copyright the idea of love. Rather, you can only copyright your expression of love in the song.

A trademark is a legal concept that protects words, names, symbols, logos, and devices used in connection with goods or services to indicate the source of those goods and services. In short, a trademark is a source identifier. This means a trademark is a "mark" used for consumers so they can easily identify and differentiate between different products and services in the marketplace.

A patent is a legal concept that grants protections to individuals who create a new invention. Technically speaking, a patent grants the holder of the patent the right to exclude others from making, using, or selling the invention.

Yes! You can freely create what are known derivative works. A derivative work is based on one or more pre-existing works. For example, you could take certain public domain documents, and add your original commentary and/or other information and obtain a copyright on that new derivative work. See Question 7 for more info on derivative works.

Next, we’ll go over copyright questions 4 – 6.

No. Again, once a work enters the public domain you are free to use it for your own benefit, including to make a profit.

No. A work in the public domain by its very nature is for everyone. You do not need to give notice to others that a work you’re using is part of the public domain.

No. Public domain work is free for you to use for any reason, including commercial profit.

Next, we’ll go over public domain questions 7 – 9.

Yes. Legally, you’re asking if you can create what are known as derivative works – works based off of another work. Because a work in the public domain is free to use by anyone for any legal reason (i.e. within the confines of the law) you can freely make new works based off of works in the public domain. In fact, this is a fairly common practice among many artists, writers, movie directors, and others – and can often be a very valuable way to make something new. For example, Marcel Duchamp created a derivative work of Leonardo Da Vinci's Mona Lisa painting by simply adding a mustache. Duchamp was free to use the painting as he wished and make a profit off of it because the Mona Lisa painting was part of the public domain.

No. Once a work enters the public domain it will remain there forever.

However, when someone makes a derivative work (i.e. variation) of the public domain work the derivative work receives copyright protection just like an original piece of work does. For example, you could take an old painting from the early 1800s, add some different colors, effects, or designs to the painting, and sell it as your own with full copyright protection – in the same way as if you created a new painting from scratch.

This is where it can get tricky – very tricky sometimes. However, there are essentially 3 broad ways in which a work enters the public domain, including: (1) the United States government created the work; (2) the term of the copyright for the work expired; or (3) the original author of the work failed to renew or satisfy other formal requirements to claim his or her interest in the copyright.

Ok, so what does all this mean? Rule 1 is fairly straightforward: Any work created by the U.S. federal government (i.e. but not necessarily a state government) is automatically part of the public domain and you’re free to use it. For example, you’re free to use the Declaration of Independence, U.S. Constitution, and other U.S. federal documents. However, you cannot use a painting created for the government by an artist unless that painting is owned by the U.S. federal government. How would you find out if the painting is owned by the U.S. federal government? Please refer to Question 10 for some analysis on this question.

Rules 2 and 3 are where stuff can get complicated. The complication arises in how a copyrighted work becomes part of the public domain. Why is this area complicated? For a number of reasons, including the following two main reasons: (i) because copyright laws have changed over the years with different lengths of time based on when the work was created or published and (ii) because it’s often difficult to determine if an author renewed his/her copyrighted work and/or properly satisfied other formal requirements to maintain copyright protections. In short, copyright protections generally survive many years after the death of the author and different people often own the copyrights to deceased authors’ works – and finding out who these people are and whether they satisfied formal copyright protections is…well…a daunting task many times. We’ll take a look at more of how these rules apply in Question 10.

Next, we’ll go over public domain question 10.

This is likely one of the most important questions to answer when dealing with public domain issues.

As mentioned in Question 9, there are 3 broad ways in which a work enters the public domain, including: (1) the United States government created the work; (2) the term of the copyright for the work expired; or (3) the original author of the work failed to renew or satisfy other formal requirements to claim his or her interest in the copyright. And as mentioned in Question 9, if a work was created by the federal government it automatically becomes part of the public domain upon its creation. However, the tougher issues arise in determining when a private work (i.e. not created by the federal government) becomes part of the public domain.

As mentioned in Question 9, the difficulty lies in determining the term of the copyright for the work expired or whether the original author of the work failed to renew or satisfy other formal requirements to claim his or her interest in the copyright (i.e. rules 2 and 3 from the above paragraph). So, how can you make these determinations? A chart will greatly help here. However, we must make an additional disclaimer (i.e. in addition to our disclaimer for the website that this information is NOT legal advice): This chart DOES NOT provide legal advice or act as a substitution for seeking a lawyer or other expert for your particular needs. In other words, talk to a lawyer before you take any action on a work that MAY be in the public domain. With that said, this chart covers works created on or after January 1, 1978 or published before 1923:

So, under this chart, works created on or after January 1, 1978 will enter the public domain after the term of protection expires. And works published before 1923 are in the public domain.

Ok, but what about works created from 1923 to 1978? This is the tricky part. We recommend you consult with a professional for these works and read Circular 15a, Duration of Copyrights, and Circular 1, Copyright Basics, to give you a better understanding of the complexity.

Finally, we’ll conclude with some main points to keep in mind when dealing with the public domain.

In this article, we covered some of the most common public domain questions. We discussed how to define the public domain, difference between the public domain and forms of intellectual property, how one can make derivative works from the public domain, how to determine when a work enters the public domain, and other rights and issues dealing with the public domain. However, keep in mind that this just covers the very basic issues associated with what constitutes a work within the public domain.

With that said, when a work becomes part of the public domain can be very fact specific and usually will require you to seek advice from a competent attorney or other specialist.