Enrico Bertacchini presented the "Creative Commons" during the Web2forDev Conference. I have known this initiative for some time now but I have never used it. I think this is because I think the things I put up on the web are for everyone to use. However, Enrico clarified that this is not really the case. By default no licence information means "All rights reserved". Something like this could be very useful for the AGROVOC Concept Server. The solution could be that everyone who contributes their knowledge to the CS agrees to the CC or Creative Science.
There are tutorials and tools available on the CC website.