Llicència "Open Government License"
Mirant altres coses, m'he topat amb aquesta llicència de copyright per a dades del sector públic
http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/
Que a més, sembla ser totalment compatible amb cc-by-4.0 i OD-ca:
These terms are compatible with the Creative Commons Attribution License 4.0 and the Open Data Commons Attribution License, both of which license copyright and database rights. This means that when the Information is adapted and licensed under either of those licences, you automatically satisfy the conditions of the OGL when you comply with the other licence. The OGLv3.0 is Open Definition compliant.