[EP-tech] Creative commons licences

[John Salter]

Hi,
Last year v4.0 of the CC licences were released (http://creativecommons.org/licenses/) e.g. http://creativecommons.org/licenses/by-nc-sa/4.0/
How should licence changes be represented over time?

Some of our content was issues under e.g. v2.5 of the license, but the field values in eprints do not link to a specific version:
cc_by_nd
cc_by
cc_by_nc
cc_by_nc_nd
...

Should these be update to include the correct version too?
cc_by_nd_4.0
cc_by_4.0
cc_by_nc_4.0
cc_by_nc_nd_4.0

 - or should we use the license URI as the value?
It means we would have to keep phrases/rendering for all license types over time, but I think this isn't much of a problem?

Any thoughts by anyone who knows about the intricacies of CC licensing?

On a related note, eprints currently has a mismatch between the rendering of licensces and their description in the workflow e.g.: 
https://github.com/eprints/eprints/blob/master/lib/lang/en/phrases/system.xml#L3259
<epp:phrase id="licenses_typename_cc_by_nd">Creative Commons: Attribution-No Derivative Works 3.0</epp:phrase>
the description (rendered on an abstract page) is 2.5:
<epp:phrase id="licenses_description_cc_by_nd"><a href="http://creativecommons.org/licenses/by-nd/2.5/">Creative Commons Attribution No Derivatives</a></epp:phrase>
(and to complete the story, rdf uses v3.0 URIs: https://github.com/eprints/eprints/blob/master/lib/cfg.d/rdf_triples_eprints.pl).

Cheers,
John