If information is to be truly public, and maximally re-usable, there should be no license-related barrier to the re-use of public information. To be completely “open,” public government information should be released completely into the worldwide public domain and clearly labeled as such. Opening data into the public domain removes barriers to information access, helps disseminate knowledge, aids in data preservation, promotes civic engagement and entrepreneurial activity and extends the longevity of the technological investments used to open information in the first place.
An open data policy must be explicit about this because copyright law varies from jurisdiction to jurisdiction. Moreover, while the U.S. Copyright Act explicitly does not include federal government works, it is silent on U.S. state and local government works. This, coupled with the additional complexities of copyright law (and ownership of various types of government data), mean special attention should be applied to all government data and the ease of its legal re-use. If the government data in question is not explicitly in the worldwide public domain, it should be given an explicit public domain dedication [such as the Creative Commons CC0 statement or a Open Data Commons Public Domain Dedication and License (PDDL)—both of which combine a waiver and a license].
- Sunlight's "Open Government Data Best-Practices Language for Making Data 'License-Free'"
- United States: Project Open Data Open License Examples
- CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
- Open Data Commons Public Domain Dedication and License (PDDL)