Wikipedia:Copyrights
The goal of Wikipedia is to create information that is available to everyone. The realities of modern copyright law demand that we pay attention to legal issues to ensure that our work can be made available, and to protect the project from legal liability.
All Wikipedia articles are licensed to the public under the GNU Free Documentation License (GFDL) without required front-cover and back-cover texts and invariant sections. Essentially, this means that the articles will remain free forever and can be used by anybody subject to minor restrictions mentioned below.
Contributors' rights and obligations
If you contribute material to Wikipedia, you thereby license it to the public under GFDL (without required front-cover and back-cover texts and invariant sections). In order to contribute, you therefore must be in a position to grant this license, which means that either
- you own the copyright to the material, for instance because you produced it yourself, or
- you acquired the material from a source which allows the licensing under GFDL, for instance because the material is in the public domain or is itself published under GFDL.
In the first case, you retain copyright to your materials. You can later republish and relicense them in any way you like. However, you can never retract the GFDL license: the material will remain under GFDL forever.
In the second case, if you incorporate external GFDL materials, you need to acknowledge the authorship and provide a link back to the network location of the original copy. If the original copy required invariant sections, you have to incorporate those into the Wikipedia article.
If you obtain special permission to use a copyrighted work from the copyright holder, please note that fact (along with names and dates) in the talk page of the article.
Never use materials that violate the copyrights of others. This could create legal liabilities and seriously hurt the project. If in doubt, write it yourself. If you find copyrighted material here that does not appear to be used with permission, remove the content, and put an explanation in the talk page. If you see that someone removed a required attribution or invariant section from an article, add it back.
Users' rights and obligations
If you want to use Wikipedia materials in your own books/articles/web sites or other publications, you can do so, but you have to follow the GFDL, which entails the following:
- your materials in turn have to be licensed under GFDL
- you must acknowledge the authorship of the article (section 4B), and you must provide access to the "transparent copy" of the material (section 4J). (The "transparent copy" of a Wikipedia article is its wiki text.) These two obligations can be fulfilled by providing a conspicuous link back to the home of the article here at wikipedia.com.
See Wikipedia and copyright issues for further discussion.