Creative Commons 4.0
"The 4.0 licenses are extremely well-suited for use by governments and publishers of public sector information and other data, especially for those in the European Union. This is due to the expansion in license scope, which now covers sui generis database rights that exist there and in a handful of other countries.
Among other exciting new features are improved readability and organization, common-sense attribution, and a new mechanism that allows those who violate the license inadvertently to regain their rights automatically if the violation is corrected in a timely manner.
The 4.0 versioning process has been a truly collaborative effort between the brilliant and dedicated network of legal and public licensing experts and the active, vocal open community. The 4.0 licenses, the public license development undertaking, and the Creative Commons organization are stronger because of the steadfast commitment of all participants."