Vicenç Riullop, 11/05/2012 21:10:
Please, forget this message, I was wrong. A work under CC-0 can be relincensed under CC-BY-SA. The question is if the officials accept also other CC licenses more restrictive than CC-0.
I'm not involved with this result, but indeed the language of the resolution would literally require you to release such photos under CC-0, to benefit from the exception. However, releasing photos under CC-BY-SA is the stated objective only a few lines above, and the Comune can't actually put any copyright requirement as the law is not about copyright (most stuff is PD) but about fees, so the point is a sub-licenseable exemption from the authorisation requests and fees. Moreover, it's true that CC-0 derivatives can follow any license (or even be copyrighted, of course) – although one might argue about what's a true derivative work which deserves its own copyright status – so I think the goal was just to say that there are no restrictions whatsoever, as for their open data initiatives (maps etc.), also mentioned in the resolution.
Nemo