On Apr 11, 2012 12:45 AM, "Sarah" <slimvirgin@gmail.com> wrote:
> Can anyone point me to the basis of the claim that cc licences are
> irrevocable? If someone were to upload an image to Flickr with a cc
> non-commercial licence, then changed her mind and broadened it to
> allow commercial use, Commons would not reject the image on the
> grounds that the first, more restrictive, licence was irrevocable.
>
> We would not allow a change of mind in the other direction, but
> allowing any change implies that we don't, in fact, regard cc licences
> as irrevocable.

A license change doesn't mean the original license has been revoked. (On Flickr or commons)

A work can be simultaneously licensed under multiple CC licenses even if they have conflicting terms. (e.g. you could a single work under both BY-ND and BY-NC-SA) That just lets the user/distributor/derivative choose which license(s) to use the work under.

-Jeremy