Yesterday’s revision post covered software licences. This post covers licences for media such as text, photographs, and images. Like software, these media are intellectual property and are protected by copyright law, which grants the creator the right to determine how they are distributed.
Copyrighted material cannot be re-used or redistributed in most circumstances. There are some small ‘fair use’ exceptions for educational use or critique, but these apply only in a few circumstances. In general, copyrighted material cannot be redistributed.
Creative Commons (CC) have created a set of standard licences that people can apply to their work if they want to distribute it but also retain some control over how it is used. These licences are made up of a number of stipulations, including:
- Attribution (BY) – the author of the work must be credited.
- NoDerivs (ND) – you are not allowed to make derivations (changes) to the work.
- ShareAlike (SA) – if you make changes you must release your work under the same licence as the original work.
- NonCommercial (NC) – you are not allowed to use the work for commercial purposes – either selling it or including it in work that will be sold.
These individual clauses are combined to make up a licence. For example, the licence for content on this blog is CC-BY-NC-SA (Creative Commons Attribution-NonCommercial-ShareAlike) meaning you can freely distribute this work, but you must credit me as the author, if you make changes you must also licence them under CC-BY-NC-SA, and you cannot sell my work or any changes that you make to it.
If you look at the bottom of every Wikipedia page, you will see that the content is licensed under CC-BY-SA, meaning you can use Wikipedia content as you please (including commercial use), and change it, but you must credit Wikipedia as the source and you must release your work under the same licence.
GNU Free Documentation License
The GNU Free Documentation License (GFDL) is similar to many open source software licences. It specifically requires that material under the licence be freely redistributable and bans any restrictions on its use. It also requires all derivative works to be released under the same licence. For my book, I avoided GFDL material because the licence appears to claim that a book containing GFDL material must also be released under GFDL – i.e. be given away for free.
The author of these works has specifically given up all rights to the work and released them into the public domain (PD). This allows anybody to use the works as they see fit. Certain works, such as most works by US government employees carrying out their duties, are automatically public domain. Of course, when using public domain works it is still a good idea to site the source and credit the author.