Re: Reviewing Last Call RDFa

Hi Tim,

Thanks for your comments on this, your time is much appreciated!

I'll address only the items that are uncontroversial from our point of 
view, leaving the remaining issues to a more detailed discussion with 
the whole group.

> ** Deployment path and architecture:
> 
> In general, is the deployment path for this spec that (a) it introduce 
> new attributes into the HTML namespace, and that conforming RDF-aware 
> HTML clients be expected in future to understand RDFa, or is it that the 
> GRDDL transform link from (b) the document or from (c) the HTML schema?

The original goal was (and still is) to introduce new attributes in the 
namespace / schema of XHTML2, XHTML1.1+RDFa, and eventually (not in this 
spec) HTML5 once it specifies a mechanism for schema extension a-la 
XHTML modularization.

However, we have received many comments asking us to "please include a 
@profile" because folks wanted to stick with GRDDL as their processing 
approach. We believe GRDDL is not the ideal technology for parsing RDFa, 
since GRDDL loses the DOM <-> RDF correspondence which is quite 
important when a human wants to extract structured data from a visually 
rendered web page. However, GRDDL is better than nothing. Thus, we 
encourage authors who *can* to add a @profile, but we don't make it 
mandatory, because the normative path to discovering the RDFa flag is 
the schema / DOCTYPE (more on DTD in response to your other comment below.)

> Is the purpose of the profile to allow GRDDL engines to find RDFA, or to 
> protect against a non-RDFa document being interpreted as an RDFa one,

The former: to help GRDDL folks.

> 4.1   "There SHOULD be a DOCTYPE declaration in the document prior to 
> the root element."  DTDs are a an obsolete technology. Suggest the spec 
> not refer to them in any way.

We would be happy to do so.... if only there was a W3C REC (and a 
validator.w3.org implementation) for validating XHTML1.1 using XML 
schema. Sadly, there isn't, and since we get a lot of "this won't 
validate!" criticism, we had to go with DOCTYPE and DTDs.

-Ben