Re: Draft Note for HTML WG

Second draft incorporating Ivan and Dan's comments. I'll be sending this as-is tomorrow morning unless I hear anything more.

Jeni

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The Task Force was put together by W3C in response to the TAG's note [1] about inconsistencies between microdata [2] and HTML+RDFa 1.1 [3]. Our goals are to perform a technical analysis of the relationships between microdata, RDFa and microformats with the goals of:

 * raising bugs where incompatibilities could be reduced through spec changes
 * documenting guidance for publishers and consumers of these formats
 * drafting mappings that help consumers merge data from different formats

Discussions are taking place on the public-html-data-tf@w3.org mailing list [4] and the products of the Task Force are currently being drafted within the wiki [5]. Of particular note is the development of an editor's draft for a mapping from microdata to RDF [6].

Several of the issues that led to the TAG's comments were addressed or raised as bugs/issues in the time between the TAG's comments being raised and the formation of the Task Force. For example, the mapping from microdata to RDF in the microdata specification was removed. RDFa 1.1 Lite (now an editor's draft [7]) was also announced during this period.

There are two outstanding HTML bugs on microdata and HTML-RDFa of interest to the Task Force, on:

 * language handling in microdata [8]
 * allowing <link> and <meta> elements in flow content when they have RDFa attributes [9]

as well as a number of issues on RDFa-Core that are rapidly being resolved.

We had some discussion with Hixie about support for multiple types from different vocabularies in microdata, but do not intend to raise a bug on this.

I anticipate there may be other issues raised, specifically on:

 * mismatches in the resolution of URLs in HTML5 and IRIs in RDF, and its impact on RDFa processing [10]
 * mismatches in the set of link relations supported by HTML5 and microformats compared to RDFa [11]
 * lack of support for representing structured HTML values in microdata [12]

The Task Force will be wrapped up by the end of the year. It may be that there are outstanding bugs when that happens, and it is likely that there will continue to be work to do to keep the guidance relevant if (as is likely) HTML5/microdata/RDFa change past that point. Part of the wrapping up of the Task Force will be recommending the appropriate groups to which to hand off that work.

[1] http://lists.w3.org/Archives/Public/public-html/2011Jun/0366.html
[2] http://dev.w3.org/html5/md/
[3] http://dev.w3.org/html5/rdfa/
[4] http://lists.w3.org/Archives/Public/public-html-data-tf/
[5] http://www.w3.org/wiki/Html-data-tf
[6] https://dvcs.w3.org/hg/htmldata/raw-file/default/microdata-rdf/index.html
[7] http://www.w3.org/2010/02/rdfa/sources/rdfa-lite/
[8] http://www.w3.org/Bugs/Public/show_bug.cgi?id=14470
[9] http://www.w3.org/Bugs/Public/show_bug.cgi?id=14114
[10] http://lists.w3.org/Archives/Public/semantic-web/2011Oct/0113.html
[11] http://www.w3.org/wiki/HTML_Data_Improvements#Link_Relations
[12] http://lists.w3.org/Archives/Public/public-vocabs/2011Nov/0022.html

-- 
Jeni Tennison
http://www.jenitennison.com

Received on Monday, 14 November 2011 17:26:40 UTC