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.
Original text of Wikipedia articles is licensed to the public under the GNU Free Documentation License (GFDL). The full text of this license is at Wikipedia:Text of the GNU Free Documentation License. Permission is granted to copy, distribute and/or modify all Wikipedia articles under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts.
Essentially, this means that the articles will remain free forever and can be used by anybody subject to restrictions mentioned below, which ensure that freedom.
Occasionally, Wikipedia articles may include text, images, sounds, or other material from external sources with different copyright terms, and which is used with permission or under "fair use" doctrine. In this case, the material will be identified as from an external source, and copyright holders of that material retain their rights.
Contributors' rights and obligations
If you contribute material to Wikipedia, you thereby license it to the public under the GFDL (with no invariant sections, front-cover texts, or back-cover texts). 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 for the versions you placed here: that 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 use part of a copyrighted work under "fair use", or if you obtain special permission to use a copyrighted work from the copyright holder, you must note that fact (along with names and dates) on the description page of the image or in the talk page of the article. It is our goal to be able to freely redistribute as much of Wikipedia's material is possible, so original material licensed under the GFDL is greatly preferred to copyrighted material (even used with permission) for our purposes.
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.
Note that copyright law governs the creative expression of ideas, not the ideas or information themselves. Therefore, it is perfectly legal to read an encyclopedia article or other work, reformulate it in your own words, and submit it to Wikipedia. (See plagiarism and fair use for discussions of how much reformulation is necessary in a general context.)
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.org.
If the Wikipedia article you wish to use contains text, images, sounds, or other material from external sources used with permission or under fair use, you must comply with the separate copyright terms for that material as well. For example, if we include an image under fair use, you must ensure that your use of the article also qualifies for fair use (this might not be the case, for example, if you were using a Wikipedia article for a commercial use that would otherwise be allowed by the GFDL).
If you find a copyright violation
When you find a Wikipedia article that contains material copyrighted by someone else which cannot be redistributed under the GFDL, delete it and place the following in the article or its talk page:
Removed probable copyright violation. This page was created with text from [insert URL or other citation here], © 19xx Foo Barbaz.
This page is now listed on page titles to be deleted. To the poster: Please either replace this message with a stub and an external link or leave this page to be deleted. If there was permission to use this material under terms of our license, then please offer some evidence of this permission on this page's talk. Please also note that the posting of copyrighted material that does not have the express permission from the copyright holder is both illegal and a violation of our policy. If you have a history or history (depending on whether the user was logged in when he wrote it) of this or if you continue violating other people's copyrights, then your IP may be temporarily blocked. Please view this as a warning -- we still welcome any original contributions by you.
See Wikipedia and copyright issues for further discussion.