WHAT TYPES OF CONTENT CAN BE CC-LICENSED?
You can apply a CC license to anything protected by copyright that you own, with one important exception.
CC urges creators not to apply CC licenses to software. This is because there are many free and open-source software licenses which do that job better; they were built specifically as software licenses. For example, most open-source software licenses include provisions about distributing the software’s source code—but the CC licenses do not address this important aspect of sharing software. The software-sharing ecosystem is well established, and there are many good open-source software licenses to choose from. An FAQ from Creative Commons’ website available at https://creativecommons.org/faq/#can-i-apply-a-creative-commons-license-to-software has more information about why we discourage the use of our licenses for software.
WHOSE RIGHTS ARE COVERED BY THE CC LICENSE?
A CC license on a given work only covers the copyright held by the person who applied the license—the licensor. This might sound obvious, but it is an important point to understand. For example, many employers own the copyright to works created by their employees, so if an employee applies a CC license to a work owned by their employer, they are not able to give any permission whatsoever to reuse the work. The person who applies the license needs to be either the creator or someone who has acquired the rights to the work.
Additionally, a work may incorporate the copyrighted work of another, such as a scholarly article that uses a copyrighted photograph to illustrate an idea (after having received the permission of the owner of the photograph to include it). The CC license applied by the author of the scholarly article does not apply to the photograph, only to the remainder of the work. Separate permission may need to be obtained in order to reproduce the photograph (but not the remainder of the article). See section 3.4 “License Enforceability” for more details on how to handle these situations.
Also, works often have more than one copyright attached to them. For example, a filmmaker may own the copyright to a film adaptation of a book, but the book author also holds a copyright to the book on which the film is based. In this example, if the film is CC-licensed, the CC license only applies to the film and not the book. The user may need to separately obtain a license to use the copyrightable content from the book that is part of the film.
