Wikipedia uses grants free access to our text in the same sense as free software is licensed freely. This principle is known as copyleft. Wikipedia content can be copied, modified, and redistributed so long as the new version grants the same freedoms to others and acknowledges the authors of the Wikipedia article used. Wikipedia articles therefore will remain free forever and can be used by anybody subject to certain restrictions, most of which serve to ensure that freedom.

We use 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 this document under the terms of the GNU Free Documentation License, Version 1.2 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.
A copy of the license is included in the section entitled "GNU Free Documentation License".
Content on Wikipedia is covered by disclaimers.

The English text of the GFDL is the only legally binding document; what follows is our interpretation of the GFDL: the rights and obligations of users and contributors.

IMPORTANT: If you want to use content from Wikipedia, read the below summary, then Wikipedia Reusers and the GNU Free Documentation License itself.


The copyrights of materials on Wikipedia edit

In order to comply with United States copyright laws and with the GFDL, all material on Wikipedia must fall into the following categories:

  • the material is licensed under the GFDL itself
  • the material is in the public domain in the United States
  • the material is available under a different free license, if the material is an image or media clip
  • the material is used under the fair use doctrine of United States copyright law

Because the Wikimedia Foundation and Wikipedia's servers are based in Florida, United States, the primary law relevant for Wikipedia is that of the United States. For re-users of Wikipedia content, it is the laws of their respective countries. Laws determining what is public domain or fair use may be different in different countries.

The public domain edit

Public domain works are simply those works which no longer have any copyright protection. This means they can be used in any way and for whatever purpose, including in Wikipedia. What is public domain depends on the country because every country has varying copyright law.

The most basic reason a work is in the public domain in the United States is that it was published before January 1, 1923 anywhere in the world. Complications arise when special cases are considered, such as trying to determine whether a work published later might be in the public domain in the U.S., or when dealing with unpublished works. When a work has not been published in the U.S. but in some other country, that other country's copyright laws also must be taken into account.

Proper attribution of the author or the source of a work, even if it is in the public domain, is still required on Wikipedia, lest the use become a case of plagiarism.

Free licenses other than the GFDL edit

All Wikipedia contributors agree to license their text in Wikipedia is released under the GFDL. However images and other media may be released under a different free license, such as a creative commons license, so long as that license allows free reuse, including partial, derivative use by commercial parties. Acceptable licenses are listed at Wikipedia:Image copyright tags#Free licenses.

Fair use edit

In general, the use of copyrighted work without the permission of the copyright holder is copyright infringement, and is illegal. As such, on Wikipedia, which is hosted in the United States, we are normally only able to use material that is not under copyright or is available under a sufficiently free license.

An important exception to this rule exists, recognized in a clause in the copyright act that describes a limited right to use copyrighted material without permission of the copyright holder — what is known as fair use (or "fair dealing" in other countries, where standards may differ).

If you decide to use part of a copyrighted work under fair use, you are legally responsible for determining whether your contributions are legal. Please read and understand fair use and Wikipedia:Fair use first. You must also make a note of that fact (along with names and dates), and, if you are contributing an image or media clip, add the appropriate image copyright tag. It is our goal to be able to freely redistribute as much of Wikipedia's material as possible, so original images and sound files licensed under the GFDL or in the public domain are greatly preferred to copyrighted media files used under fair use. See Wikipedia:Boilerplate request for permission for a form letter asking a copyright holder to grant us a license to use their work under terms of the GFDL.

Never use materials that infringe the copyrights of others. This could create legal liabilities and seriously hurt the project. If in doubt, write it yourself.

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. However, always cite sources, both to ensure verifiability and for fair attribution. (See plagiarism and fair use for discussions of how much reformulation is necessary in a general context.)

Copyright violations edit

Wikipedia has no tolerance for copyright violations in our encyclopedia, and we actively strive to find and remove any that we find.

Copyright owners: If you believe Wikipedia is infringing your copyright, you may request immediate removal of the copyright violation. Alternatively, you may contact Wikipedia's designated agent under the terms of the Online Copyright Infringement Liability Limitation Act.

Contributors' rights and obligations edit

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 that 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, as a requirement of the GFDL, 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; it is however very desirable to replace GFDL texts with invariant sections by original content without invariant sections whenever possible.

Reusers' rights and obligations edit

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. If you are simply duplicating the Wikipedia article, you must follow section two of the GFDL on verbatim copying, as discussed at Wikipedia:Verbatim copying.

If you create a derivative version by changing or adding content, this entails the following:

  • your materials in turn have to be licensed under GFDL,
  • you must acknowledge the authorship of the article (section 4B), and
  • keep the history section, and note any changes, including "at least the title, year, new authors, and publisher" (section 4I)
  • you must link back to the original Wikipedia article to "preserve the network location [...] given in the Document for public access to a Transparent copy [...] and likewise the network locations given in the Document for previous versions it was based on" (section 4J)

You may also be able to partially fulfill the second and third obligations by providing a conspicuous direct link back to the original Wikipedia article; however, your changes should still be noted in the history section. However, please note that the Wikimedia Foundation makes no guarantee to retain authorship information and a transparent copy of articles. Therefore, you are encouraged to provide this authorship information with your derived works in addition to including the link.

Special cases edit

Images edit

Images and photographs, like written works, are subject to copyright. Someone owns them unless they have been explicitly placed in the public domain. Images on the internet need to be licensed directly from the copyright holder or someone able to license on their behalf. In some cases, fair use guidelines may allow a photograph to be used. And unlike text, images may be used on Wikipedia if they are released under a free license other than the GFDL.

Image description pages can be tagged with a special tag to indicate the legal status of the images, as described at Wikipedia:Image copyright tags.

Linking to copyrighted works edit

Linking to copyrighted works is usually not a problem, as long as you have made a reasonable effort to determine that the page in question is not violating someone else's copyright. If it is, please do not link to the page. Whether such a link is contributory infringement is currently being debated in the courts, but in any case, linking to a site that illegally distributes someone else's work sheds a bad light on us.

Others? edit

What should go here?

See also edit

Further discussion...