By repeating false things they will be not more true. IT'S ABSOLUTELY FALSE THAT GFDL HAS A PRINCIPAL AUTHOR CLAUSE. This clause only refers to a title page. READ THE LICENSE PLEASE. Wikipedia hasn't such a thing. Attribution in the GNU FDL is done by copyright notices or the section called History. "To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page: Copyright (c) YEAR YOUR NAME. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". This means: Follwowing this way of attribution the name of the autor can never dissapear. Verbatim copying: "You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the COPYRIGHT NOTICES, and the license notice saying this License applies to the Document are reproduced in all copies" (my empasis). Modification: "D. Preserve all the copyright notices of the Document." Important is the following clause: "I. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled "History" in the Document, create one stating the title, year, AUTHORS, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence." (my emphasis) It is possible to ignore this? I do not think so. There is a strong obligation that every GFDL document which is modified must have a section entitled History. The only thing in the Wikipedia which can be regarded as a section history is the version history which is also the way in which authors are given credit. One entry with the name/IP of the contributor and the date in the version history has two functions: 1. it is a substitution of the copyright noctice, 2. it is part of the section history. A lot of people in the German Wikipedia believe that the only way to fulfill the GFDL strictly is to reproduce the whole version history resp. the names of all contributors. "Das Wikipedia Lexikon in einem Band" was a cooperation between Bertelsmann and the German chapter. It has a long list of ALL contributors see e.g. http://books.google.com/books?id=BaWKVqiUH-4C&pg=PT979 The Directmedia Offline Wikipedia CDs/DVDs have reproductions of the version histories. I would like to say one thing very clear: IT IS THE RIGHT OF THE AUTHOR AND NOT A THIRD PARTY RIGHT TO CHOOSE THE WAY OF ATTRIBUTION IN THE CC-BY-SA LICENSE. The attribution in the GFDL is described by the license. WMF or FSF has NO RIGHT to choose a specific interpretation. WMF has NO RIGHT to relicense the old content according to the proposed "Copyright Policy" containing the CC-BY-SA attribution "expectations". Each user has to agree EXPLICITELY to the "Copyright Policy" as part of the contract between the WMF and him. May be it is legal to make this agreement valid for older contributions of the same user. But the policy cannot bind users no more active. Third party CC-BY-SA text content cannot be imported if there is'nt an EXPLICITE statement that the creator allows the attribution policy. It is possible to substitude the normal attribution by giving instead an internet adress BUT ONLY THE CREATOR CAN CHOOSE THIS POSSIBILITY. If you will import CC-BY-SA content you have to obey the author's way of attribution. If there is no specification the name has to be mentioned. For this contribution the attribution policy (incl. link to a list of authors if more than five) ISN'T VALID! Klaus Graf