Development of Creative Commons licenses

[Gregor Hagedorn <g.m.hagedorn AT gmail.com>]

There are many cases (I'm thinking websites in particular) where an author lists their CC license in a single location, such as the side panel of a blog using a CMS.  In these cases it may be difficult to implement this the way you suggest.  NC2013 would appear to be applicable for all content, from the earliest post from, say, eight years ago to one made yesterday.

I agree, but I think this is not principal problem. The author would be free to update the license every year (she or he holding copyright, being able to re-license). The fact that parts expire at an earlier date can be discovered only through web archiving mechanisms (e.g. webcitation could automatically display all NC-expired works). The problem of copyright holders changing licenses is not unique to this, it is a major problem with using CC-licensed Flickr images.

An alternative is to declare the length of time rather than the year the clause would end.  So, NC7 would mean all my work is under an NC license until seven years after it's original publication.  This, of course, will need to be used in tandem with clearly stated dates of publication, which I believe is so in many cases, anyway.  And this is probably an easier practice than to state individual licenses for every work.

I think the opposite. Discovering the relevant licensing date (which may be different from the date of publication) will be very difficult in most cases. With a "last year" of NC-condition statement being part of the license URL I can go into any form of webarchiving with machine-driven discovery. With an NC7-url only humans can facilitate re-use, with deep research and in most cases significant uncertainties (translating into risk of copyright violations). I may overlook something... Are the webserver "last modified" dates still reliable on archived copies?

I think the utility and reliability of automated and legally save discovery should decide this. In principle I would be happy with either version (expiration-year-dated or duration-dated).

I also feel the meaning of NC2013 is a little ambiguous.  Does it mean it's no longer NC as of January 1 2013, or January 1 2014?  If I'm confused, there are probably others out there who would be, too =) 

I agree. I think there could be value in  NCexp2013. It just looks more complicated. It should be visually intuitive. Some further tests, what do you think of:

CC BY-NC- exp2013-SA
  : I think this is confusing, because the link of expire to condition is not unambigous
CC BY-NCexp2013-SA
CC BY-NC/exp2013-SA
CC BY-NC(exp2013)-SA

Any other ideas?

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Of course, the model of having the license change to an arbitrary other license is possible. But at least I would initially think if someone say "the license _expires_" that it simply expires, not that it is replaced by another license. I find "license expires" confusing (when it really means: "is replaced by another license", whereas I find "non-commercial condition expires 2013" intuitive, i.e. the remaining CC conditions continue to be applicable.

Gregor