How Work Enters the Public Domain
Some things are not eligible for intellectual property protection and are automatically in the public domain. This includes:
Generic words, titles and short phrases
Work also enters the public domain when its IP protection expires. For patents, this term is generally 20 years from application (14 years from issuance for design patents). On occasion, patents may be extended for up to five years. They may also expire early if the patent holder does not pay maintenance fees.
Copyright terms are a bit more complicated, as the law has changed several times over the past century.
Under U.S. law, works published before Jan. 1, 1923, are in the public domain.
Works published between 1923 and 1977 will generally enter public domain 95 years after their first publication date. Those published before 1964 are already public domain if they were not properly renewed.
Works created before 1978 but not published until between 1978 and 2002 will enter the public domain either 70 years after the author's death or at the end of 2047, whichever is longer. Works by unknown authors or done for hire will remain protected at least until the end of 2047.
Works created after 1977 become public domain works 70 years after the creator's death. Corporate works become public domain either 95 years after publication or 120 years after creation, whichever comes first, with some caveats.
A copyright owner may also choose to release the work to the public domain. These works usually contain an explicit statement such as, "This work is dedicated to the public domain." Do not confuse public domain with Creative Commons licensing, in which the author licenses the public to use a work with various restrictions but without needing to request permission.
The Internet and Public Domain
Although much of the information posted to the Internet is freely available to the public, the Internet is not in and of itself public domain. Most of the material posted there is protected by copyright, regardless of whether the author has put a copyright notice on it. When you post your work online, it's a good idea to include a copyright notice to remind people it's protected.
In addition, making software or PDF files easily downloadable is not the same as placing it in the public domain. You may use the copy you downloaded for your personal use, but unless it includes a license stating otherwise, you may not resell it, distribute it or claim it as your own work.
That said, fair use still applies to material on the Internet, so if you want to use a small amount for educational purposes or commentary, this is generally permissible. Overall, it's best to ask permission before using material from the Internet. You can use a copyright request for this.
Government Website Content and Public Domain
Federal government works-material created by federal government employees as part of their jobs-are automatically in the public domain in the United States. This includes material published on the Internet, so much of what you find on government websites (generally *.gov and *.mil sites) is public domain and free for you to use or republish.
However, not all the material published on these sites was government-produced. The site may:
Republish copyrighted works under license
Publish excerpts of copyrighted works under fair use
Allow members of the public to contribute photos or other works to some sections of a site
Commission works by independent contractors
Unless the website states differently, the authors of these types of works hold the copyright to them. In addition, the government may hold copyrights transferred to it by the creator. Finally, state and local governments may, and often do, retain copyright to work created by their employees, including material on their websites.
In short, it's a good idea to read the disclaimers on the site before assuming material posted there is public domain. Images and other materials credited to a specific person or organization are likely protected.
Using Public Domain Property
You may use public domain property any way you wish, including republishing it as is and creating derivative works. If you've added enough of your own creativity to the new work, you can even copyright the work, although protection will only extend to the new material, not any words copied directly. You cannot copyright an abridged version or anthology that you have not added anything new to.
Keep in mind that public domain laws in other countries differ. The United States has treaties and conventions with many other countries, but works that have entered the public domain the the U.S. may not have in other countries, and vice versa.
This article contains general legal information and does not contain legal advice. Rocket Lawyer is not a law firm or a substitute for an attorney or law firm. The law is complex and changes often. For legal advice, please ask a lawyer.