GNU Free Documentation License

Copies may also be sold commercially, but, if produced in larger quantities (greater than 100), the original document or source code must be made available to the work's recipient.The license also has provisions for the handling of front-cover and back-cover texts of books, as well as for "History", "Acknowledgements", "Dedications" and "Endorsements" sections.These features were added in part to make the license more financially attractive to commercial publishers of software documentation, some of whom were consulted during the drafting of the GFDL.However, at the request of the Wikimedia Foundation,[6] version 1.3 added a time-limited section allowing specific types of websites using the GFDL to additionally offer their work under the CC BY-SA license.These exemptions allow a GFDL-based collaborative project with multiple authors to transition to the CC BY-SA 3.0 license, without first obtaining the permission of every author, if the work satisfies several conditions:[6] To prevent the clause from being used as a general compatibility measure, the license itself only allowed the change to occur before August 1, 2009.In the case of Baidu, Wikipedia representatives asked the site and its contributors to respect the terms of the licenses and to make proper attributions.Some reasons for this are that the GFDL allows "invariant" text which cannot be modified or removed, and that its prohibition against digital rights management (DRM) systems applies to valid usages, like for "private copies made and not distributed".In 2003, Richard Stallman said about the above sentence on the debian-legal mailing list:[23] This means that you cannot publish them under DRM systems to restrict the possessors of the copies.[28] Wikivoyage, a web site dedicated to free content travel guides, chose not to use the GFDL from the beginning because it considers it unsuitable for short printed texts.