There is a huge library of non-copyrighted content out there that largely remains untapped. This content, known as “public domain” content, is made up of works that have had their copyright term expire. However, there are serious issues with using content that’s in the public domain that you may not anticipate. Here are just a few.

When does something go into the public domain and lose copyright protection?

Just because something is found on the Internet does not mean that it’s in the public domain. Even memes like Nyan Cat and Keyboard Cat have copyright protection belonging to their creator – you’re just getting a license to use them freely (see the case where WB and 5th Cell were sued over their usage in Scribblenauts).

Certain works will always be in the public domain. These include:

Figuring out the actual term for copyright can be quite complicated, depending on when the work was created. Here’s a great chart that should help sort things out a bit.

When things are a bit messy, one way to get to the bottom of it is to contact the author of the work or whoever currently owns the copyright. You can inquire into the copyright status and get copies of the appropriate documents that show current ownership and protection status. You could also ask about getting a license to use the works, if they are indeed still protected by copyright.

What about a longer series that is half-in, half-out of copyright?

For a series of books or other works that spans a long period of time, such as the Sherlock Holmes novels, the copyright status is trickier. Lucky for us, the courts have answered just this question in a recent case about the venerable detective.

It turns out that the copyright on all but 10 Sherlock Holmes books has expired. That means that Sherlock Holmes as a character and the events of many of the books are in the public domain. However, the events and stories in those 10 copyrighted books are still protected. This is important, since it means that certain things cannot be used if you are making derivative works based on Holmes.

So if something’s in the public domain, I can use it freely?

Not necessarily. Even if something does not have copyright protection, it may be protected by trademark. Take Tarzan, for instance. The first nine Tarzan novels were published prior to 1923, which puts them in the public domain.

Wait just a minute, though. If you search the USPTO’s TESS search engine, you’ll see that the Edgar Rice Bourroughs estate holds multiple trademark registrations in the Tarzan brand.

What does that mean? Essentially, while you can use the story ideas and specifics in those public domain Tarzan stories, you can’t use the Tarzan brand name as a trademark if it would be likely to confuse consumers as to the source of those goods. This can be confusing, for sure.

Basically, if you were to release your own series of Tarzan books, you would most likely be infringing on the Tarzan trademarks. However, if you wrote your own story about Nazrat, the ape man, using ideas and other non-trademarked names from those public domain stories, you’d probably be okay. Or, if you used the Tarzan name in a non-trademark way (not identifying the source of goods or services), then you would probably be okay.

Of course, you would probably be opening yourself up to a trademark infringement lawsuit one way or the other, meritless or not.

Don’t go it alone

If you’re looking to leverage some of the public domain content, why not check with a lawyer first? The lawyer may be able to do a more thorough copyright and trademark review on the use of that content and inform you of the risks in using that content. Also, check out my two FREE game development legal eBooks, including my book about Fair Use.

Thanks to Elon Musk and SpaceX for making their launch photos public domain! Check out more of them on Flickr!