Licenses on MediaWiki.org
All textual content of MediaWiki.org is released under one of two licenses.
- The public domain help pages are, as the name implies, released into the public domain (PD)
- All other pages are released under the Creative Commons Attribution-Share Alike 3.0 Unported license (CC BY-SA).
Both licenses allow anyone to re-use the content in any way they choose. This includes charging money for access to the content, distributing it wherever and however they like, and modifying it in any way they see fit. The main differences between the two licenses are:
- If you alter CC BY-SA content, your changes must also be released under the CC BY-SA.
- Any use of CC BY-SA content must provide credit to the authors.
Note: This is a very basic comparison to highlight the main points. There are other differences that have not been mentioned here. Please seek proper legal advice if you are in any doubt about what you are and are not allowed to do with material released under either license.
Image-specific permissions are located on the images' description pages.
How to spot the license
The public domain help pages are all contained within the "help" namespace. This means that their page titles will all begin Help: (for example Help:Contents). They have also been given a thick blue border to make them stand out (as you can see if you follow the above link).
Considerations for PD contributors
If you are going to contribute to the PD help pages, please ensure that all contributions come from public domain sources. This means that either you have written it yourself, or you have copied it from another source that is clearly and unambiguously released into the public domain.
Most importantly, do not contribute content released under the CC BY-SA or GFDL or any other "open" license. It may appear that this is acceptable, because there is a certain amount of similarity between the licenses, but PD is not compatible with any other license in the way that the content with any other license can't be relicensed into PD (except that you are the author of the content). However, PD content can always be relicensed into any license.
- Do not copy or transfer content from meta.wikimedia.org, Wikipedia or any other Wikimedia projects into the Help: namespace as they are all released under the CC BY-SA. You may of course copy it to other places on MediaWiki.org, however.
- Within the site, do not move pages from any other namespaces into the Help: namespace.
The exception to the above rules is if you are the sole author of content for a page, in which case you may relicense your own material by posting it to the Help: namespace as public domain. Note that this is a one way process - you cannot change your mind once it has been done!