We are considering upgrading the default copyright license for Wikimedia to Creative Commons Attribution-ShareAlike 4.0. This proposed amendment will be available for discussion for at least thirty days (until November 8, 2016).
Non-text media: Non-text media on the Projects are available under a variety of different licenses that support the general goal of allowing unrestricted re-use and re-distribution. When you contribute non-text media, you agree to comply with the requirements for such licenses as described in our Licensing Policy, and also comply with the requirements of the specific Project edition or feature to which you are contributing. Also see the Wikimedia Commons Licensing Policy for more information on contributing non-text media to that Project.
Public domain content: Content that is in the public domain is welcome! It is important however that you confirm the public domain status of the content under the law of the United States of America as well as the laws of any other countries as required by the specific Project edition. When you contribute content that is in the public domain, you warrant that the material is actually in the public domain, and you agree to label it appropriately.
Re-use: Re-use of content that we host is welcome, though exceptions exist for content contributed under "fair use" or similar exemptions under copyright law. Any re-use must comply with the underlying license(s).
When you re-use or re-distribute a text page developed by the Wikimedia community, you agree to attribute the authors in any of the following fashions:
Through hyperlink (where possible) or URL to the page or pages that you are re-using (since each page has a history page that lists all authors and editors);
Through hyperlink (where possible) or URL to an alternative, stable online copy that is freely accessible, which conforms with the license, and which provides credit to the authors in a manner equivalent to the credit given on the Project website; or
Through a list of all authors (but please note that any list of authors may be filtered to exclude very small or irrelevant contributions).
If the text content was imported from another source, it is possible that the content is licensed under a compatible CC BY-SA license but not GFDL (as described in "Importing text", above). In that case, you agree to comply with the compatible CC BY-SA license and do not have the option to re-license it under GFDL. To determine the license that applies to the content that you seek to re-use or re-distribute, you should review the page footer, page history, and discussion page.
In addition, please be aware that text that originated from external sources and was imported into a Project may be under a license that attaches additional attribution requirements. Users agree to indicate these additional attribution requirements clearly. Depending on the Project, such requirements may appear for example in a banner or other notations pointing out that some or all of the content was originally published elsewhere. Where there are such visible notations, re-users should preserve them.
For any non-text media, you agree to comply with whatever license under which the work has been made available (which can be discovered by clicking on the work and looking at the licensing section on its description page or reviewing an applicable source page for that work). When re-using any content that we host, you agree to comply with the relevant attribution requirements as they pertain to the underlying license or licenses.
Modifications or additions to material that you re-use: When modifying or making additions to text that you have obtained from a Project website, you agree to license the modified or added content under CC BY-SA 4.0 or later (or, as explained above, another license when exceptionally required by the specific Project edition or feature).
When modifying or making additions to any non-text media that you have obtained from a Project website, you agree to license the modified or added content in accordance with whatever license under which the work has been made available.
With both text content and non-text media, you agree to clearly indicate that the original work has been modified. If you are re-using text content in a wiki, it is sufficient to indicate in the page history that you made a change to the imported text. For each copy or modified version that you distribute, you agree to include a licensing notice stating which license the work is released under, along with either a hyperlink or URL to the text of the license or a copy of the license itself.