Wikipedia:Multi-licensing 

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All text edits to Wikipedia fall under the GNU Free Documentation License (GFDL) with the copyright being retained by the original author. This is a guide for using multiple licensing of one's contributions made to Wikipedia so that they are in the public domain or licensed under alternative licenses in addition to the GFDL. A number of users have chosen to release their contributions under the Creative Commons Attribution Share-Alike license (known as "CC-by-sa"), or some other license, or even to release their contributions into the public domain. Dual- or multi-licensing is not required or suggested by Wikipedia, but some users—for a variety of ideological or other reasons—prefer to release their contributions under a wider range of terms.

Contents

How it works

While all articles in Wikipedia are derivative works based on the first contribution made to the article, each article must be licensed under the GFDL. However, individual contributions are not by themselves derivative works because they do not contain any of the original work, as the copyright still remains with the author. It is within one's rights to license those contributions under any terms one prefers, so long as one does it in addition to also being covered under the GFDL.

Example: David and Diana are dual-licensors under the GFDL and an incompatible License A. Gustav only licenses under the GFDL. Both the GFDL and License A may be used in the following cases:

For instance,

  1. David creates an article
  2. Diana makes an edit.
  3. David makes an edit.
  4. Gustav makes an edit.
  5. Diana makes an edit.

Under this scenario, versions 1 through 3 are available under the GFDL and incompatible License A, but version 4 is only available under the GFDL. Version 4 may be fully available if Gustav's edit was a trivial one that wouldn't cause anyone to care, such as fixing a typographical error. Version 5 is probably available if it subtracts the modification made by Gustav. For instance, if Gustav adds a specific paragraph that is separate from the rest of the article, the article minus that paragraph can be used under both licenses. For all other usage, such as if Diana's modification was derived from Gustav's modification, you must convince Gustav to release his contributions under License A to use them. In the case of Version 4 and 5, one must use some common sense in order to tell what qualifies as being covered under both licenses and what does not.

Controversy

The case for multiple licenses

The case against multiple licenses

Why it might not matter

Using multiple licenses

In general, users make their multi-licensing desires known on their user page by way of a banner or some description of their wishes (See User:Jamesday for a complicated example). This is often simply accomplished by adding a pre-made template (such as {{DualLicenseWithCC-BySA}}). See the full selection of licensing templates available.

The scope of a license may vary. For instance, a user may choose to license main namespace changes in one license and talk namespace changes in another. In addition, a user may consider releasing all minor changes into the public domain in order to avoid the problems that trivial changes may have in trying to release an article in a specific license. At the same time, meaningful non-minor changes can be released under a more restrictive license. In the case of the GNU licenses, one can specify certain restrictions, such as specifying a particular version of the license instead of any.

Using the GFDL only

Unless you explicitly specify otherwise, all contributions to Wikipedia are licensed under the GFDL; therefore, if you elect not to adopt additional licenses, no action is necessary. Even if you use the GFDL exclusively, you may wish to communicate your preference on your User page, such as by using {{NoMultiLicense}}.

List of terms for use

See also

References