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TAG Product: HTML Data


The TAG's HTML5 Last Call Review resulted in the TAG raising issues on microdata and RDFa Last Call Working Drafts. The TAG recommended that the W3C set up a Task Force to investigate whether the languages could be brought together, or to aid users (both publishers and consumers) in understanding the strengths and weaknesses and to ease transitions between the syntaxes.


Following the TAG's note, several of the issues that led to the TAG's comments were addressed or raised by individuals as bugs or issues on microdata or RDFa. For example, the mapping from microdata to RDF in the microdata specification was removed. RDFa 1.1 Lite was also announced.

Following discussions with key players, the HTML Data Task Force began in mid September and was limited to a technical analysis of the relationships between microdata, RDFa and microformats with the goals of:

Discussions took place on the public-html-data-tf@w3.org mailing list and were captured in the wiki, which continues to be available for the community to capture best practice in the use of HTML data.

The HTML Data Task Force identified a number of issues to ease the alignment of microdata and RDFa. Most of these were raised as bugs on the relevant specifications.

Two SWIG Notes were created by the Task Force:

It is hoped that the Microdata to RDF Working Draft will be taken forward to Recommendation when microdata moves forward to Recommendation status, but at this time there is no Working Group in a position to do this.

The TAG resolved on 19 January 2012 that the status recorded above is the basis on which the TAG is closing out it's work on Microdata/RDFa.

Next Steps

The TAG will continue to monitor developments in HTML data, but has no specific further actions planned.

TAG Issues, Actions and Tracker Product Page


This TAG product was not the result of a specific TAG issue.


The TAG actions associated with this project were:

Tracker products

This TAG product was not tracked as a Tracker product.

Available versions of this document:

Latest: http://www.w3.org/2001/tag/products/htmldata.html

This version: http://www.w3.org/2001/tag/products/htmldata.html-2012-04-23

Previous versions: (none)