[whatwg] Creative Commons Rights Expression Language

Dan Brickley danbri at danbri.org
Thu Aug 21 00:49:53 PDT 2008

+cc: Ben Adida

Tab Atkins Jr. wrote:
> On Wed, Aug 20, 2008 at 5:22 PM, Bonner, Matt <matt.bonner at hp.com 
> <mailto:matt.bonner at hp.com>> wrote:
>     Hola,
>     I see that the Creative Commons has proposed additions to HTML
>     to support licenses (ccREL):
>     http://www.w3.org/Submission/2008/SUBM-ccREL-20080501/
>     As an example, they offer:
>     <div about="http://lessig.org/blog/"
>     xmlns:cc="http://creativecommons.org/ns#">
>        This page, by
>        <a property="cc:attributionName" rel="cc:attributionURL"
>              href="http://lessig.org/">
>           Lawrence Lessig
>        </a>,
>        is licensed under a
>        <a rel="license" href="http://creativecommons.org/licenses/by/3.0/">
>          Creative Commons Attribution License
>        </a>.
>     </div>
>     Unless I missed something in the HTML5 spec, at the least this would add
>     the "property" attribute to <a>.  Wouldn't ccREL be expressed better
>     using <link> instead of <a>?
>     Matt
>     --
>     Matt Bonner
>     Hewlett-Packard Company
> The whole thing would be best expressed as a microformat, as the entire 
> thing can be made just as machine- and human-readable without having to 
> introduce an entire new addition to html.  I think someone is a little 
> confused about the important of CC...
> (Note: the someone is not you, Matt, but the drafters of this proposal.  
> Also, I love CC as much as the next guy, but there's absolutely no 
> reason to extend html to accomodate it, as everything they want to 
> express can be done in existing html and formatted as a microformat.)

I encourage you to (re)-read 
http://www.w3.org/Submission/2008/SUBM-ccREL-20080501/ ... the spec 
explains that all of CC's concrete markup requirements are addressed by 
the HTML additions in the RDFa spec. It does not propose *any* new HTML 
markup to address CC's specific needs. Instead, they're telling the 
world that CC's needs (including their own requirement for independent 
extensions) are well-handled by RDFa.

RDFa adds a set of attributes; 
has a full list. The ccREL spec shows these in an XHTML+RDFa XHTML 
format. There's a strong case to add them to HTML5 too, in my view.

In other words, adding 'about', 'property', 'resource', 'datatype' and 
'typeof' and a namespace-URI association convention to HTML5 wouldn't 
merely be addressing the important needs of the Creative Commons 
community. It would allow the expression of properties defined by any 
decentralised community, without the need for central coordination. This 
includes not just CC, but every group worldwide who are extending and 
customising CC for their own needs. Not just FOAF, but groups extending 
it for modelling forum posts and social media (eg. SIOC), or opensource 
projects (DOAP). Not just Dublin Core, but the huge range of projects 
that extend it to handle educational metadata (which itself varies 
nationally), rights, aggregation, classification etc. The addition of 
the RDFa attributes would allow HTML5 to carry structured data expressed 
in all/any of these vocabularies.

The Microformats.org community have done wonderful work and have 
inspired many others, but it is unfair on them (and unrealistic) to 
pressure their community, mailing lists and wiki by expecting their 
process to be a central bottleneck for all markup extensions to HTML. 
The Web serves a massive and fast growing community, many of whom don't 
speak English and are whose markup needs aren't core business for 
Microformats.org. By using RDFa and associating each vocabulary with a 
URI, we can spread the workload a bit more evenly.

Note also that every new vocabulary initiative at Microformats.org 
creates real and non-trivial work for parser writers, as well as work 
for vocabulary authors in specifying what it means to mix each pair of 
vocabularies. For ccREL (and FOAF, Dublin Core, SIOC, DOAP, ...), this 
is largely handled by RDF/RDFa: it can be freely mixed with any other 
RDF vocabulary, and reliably parsed by generic parser code. The tradeoff 
here is that the markup is less hand optimised for beauty than with 
microformats. (When extra-pretty custom markup is important, RDF 
provides GRDDL as a way of using XSLT to specify a mapping into its 
common data model.)

For more on RDFa, see the primer, http://www.w3.org/2006/07/SWD/RDFa/primer/

For a microformat parser that also handles RDFa, see 
http://buzzword.org.uk/cognition/   ... or an RDF toolkit that also 
parses some popular microformats, see http://arc.semsol.org/

For RDFa parsing in Javascript, see 



ps. my slides from a recent talk on rdf and microformats are here, if 
anyone's interested. It's more about how enthusiasts from each effort 
can learn from each other, than about the technical detail: 
http://www.slideshare.net/danbri/one-big-happy-family/ via 


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