GFDL / CC by-sa compatibility

Anthony DiPierro wrote:

>I'd like to see this, because it seems quite suspect.
A quick check found this Wikipedia-l post:
http://mail.wikipedia.org/pipermail/wikipedia-l/2003-June/010512.html

I'm sure there are others which cover other points but I don't have the time 
to look through them all. 

>Right.  You can't add another license onto the derivative work, 
>but you can add another license onto your changes.

AFAIK that is true. In fact I have a statement on my user page that explicitly 
says that any text I write can be considered to be released under the GNU FDL 
and the CC by-sa (it is up to the third party to choose which). But the text 
that Wikipedia itself is able to relicense (which would be the derivative 
work of all contributors to a single article)  is only under the GNU FDL. 
Some other people state on their user pages that any text they write is in 
the public domain. So I guess that is also a type of dual license. This is 
possible due to the diff function. However, all that is a choice by the 
individual contributors. 

Things get messy if we would try to force everybody to dual license - we need 
the consent of all users to make that happen. That is, as I have said, not 
possible. The interim result of any such effort would be odd indeed; all the 
individual edits made after the license change would be dual licensed but the 
article as a whole could only be under the GFDL until all the GFDL text is 
replaced by dual licensed edits.   

>"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)."  I don't see anything about 
>freeing downstream users from the more onerous requirements.  

That is just the copyright statement that is required by the GFDL to be used 
verbatim for any GFDL text that does not have invariant sections, front-cover 
texts, or back cover texts. Read below that to find out how we recommend 
third parties to adhere to the the GFDL. It is much less restrictive than the 
letter of the GFDL. 

>Specifically, where does it say that you grant people permission 
>to add non-GFDL content to derivitive works?

Fair use is an overarching doctrine of the copyright law. We also have a 
policy on fair use spelled out on that page. 
http://en2.wikipedia.org/wiki/Wikipedia:Copyrights#Fair_use_materials_and_special_requirements

>Sure, they can use the text, but they can't use the images.  
>But hey, you're saying they can, because RMS said so.  Maybe 

What is fair use for us (a non-profit with an educational purpose) is much 
less restrictive than what is fair use for others (esp. for profits and 
organizations with an advocacy purpose). It is legally up to them to due 
their 'due diligence' in making sure their use of what we dub 'fair use' 
files can also be considered to be 'fair use' for them.

But this does introduce a poison pill into our database that makes it more 
difficult for many downstream users to use our content. We should therefore 
make their due diligence job easier by having forms in MediaWiki's upload 
page that will categorize files based on license and use restrictions. Then 
downstream users can more easily exclude files that they cannot legally use. 
Last time I checked this is part of the development path of the developers. 

-- Daniel Mayer (aka mav)