Quezi

Photo by ϻicκγ - CC0

Every country has a notion of the public domain—where creative and scientific works older than a certain age are available to everyone as part of humanity’s shared culture. But what if you want to dedicate your own creative or scientific work to humanity? Many countries don’t allow you to do that, and automatically apply full copyright restrictions to your work.

In a few countries you can simply announce that you dedicate your work to the public domain, so that other people can use the content however they wish. If your government does not allow its citizens this freedom, you can instead apply the CC-0 (CC zero) license to it. You can think of CC0 as meaning “no rights reserved”.

The CC0 license has a dual nature. When applied to a creative or scientific work, it dedicates the work to the public domain if that is possible. Otherwise, as a fallback, it licenses free use of the work to the maximum extent possible. This dual nature means that, for pretty-much any practical purpose, CC0-licensed works are “as good as in the public domain”.

As a content creator, you can add a CC0 designation to your work, or you can announce it more formally by going to the Creative Commons site and generating some HTML code to record your designation in a machine-readable way.

As a content consumer, if you acquire a CC0-licensed work you know that the person licensing it has relinquished any claim upon it. You still need to consider the context of the work, to determine whether anyone else might have some claim upon it. For example, in some situations the subject of a photo may have some control over its use even if the photographer has abandoned their control of the photo.

See the CC0 FAQ for more details.

CC-zero is a new (March 2009) license, and it may be some time before it’s widely-used, but it is already being employed for the publication of scientific research into protein structures and the human genome, and many Flickr photographers are annotating their work with CC0 even though Flickr hasn’t set up a category for it yet.

Oh, and it’s not to be confused with the delightful CC-Zero Micro Kit Car.