From Social Patterns
The public domain is a range of abstract materials—commonly referred to as intellectual property—which are not owned or controlled by anyone. The term indicates that these materials are therefore "public property", and available for anyone to use for any purpose. The public domain can be defined in contrast to several forms of intellectual property; the public domain in contrast to copyrighted works is different from the public domain in contrast to trademarks or patented works. Furthermore, the laws of various countries define the scope of the public domain differently, making it necessary to specify which jurisdiction's public domain is being discussed.
From Wikipedia's article on public domain licensing at Wikipedia itself:
For all practical purposes on Wikipedia, the public domain comprises copyright-free works: anyone can use them in any way and for any purpose. Proper attribution to the author or source of a work, even if it is in the public domain, is still required to avoid plagiarism.
The public domain is generally defined (e.g. by the U.S. Copyright Office) as the sum of works that are not copyrighted, i.e.
- that were not eligible for copyright in the first place, or
- whose copyright has expired.
However, there is no such thing as the public domain on the Internet. International treaties, like the Berne Convention, are not self-executing and do not supersede local law. There is no globally valid "International Copyright Law" that would take precedence over local laws. Instead, signatory countries of the Berne Convention have adapted their laws to comply with the minimum standards set forth by the treaty, often with stronger provisions than required. Whether or not something is copyright-free in some country depends on the laws of individual countries.
Wikipedia, and the Wikimedia Foundation, its legal body, are based in Florida, United States. Although legislation is sometimes unclear about which laws are to apply on the Internet, the primary law relevant for Wikipedia is that of the United States. For re-users of Wikipedia content, it is the laws of their respective countries.
In the U.S., any work published before January 1, 1923 anywhere in the world is in the public domain. Other countries are not bound to that 1923 date, though.
If you can get all your stakeholders (from the owner of the site to the participants) to agree to place as much content as possible in the public domain, or to make public domain licensing the default for collaborative content, then you will enable the greatest possible reuse and remixing of your community's content, with the consequence being a giving up of control over how the content may be used or altered by others.
(Creative Commons has a public domain option.)
- Ethical Public Domain
- Wikipedia: Public domain
- Public Domain Information Project (Royalty-free Music)
- Creative Commons public domain dedication
- When U.S. Works Pass into the Public Domain