- From: Doug Schepers <schepers@w3.org>
- Date: Fri, 10 Oct 2008 14:04:43 -0400
- To: Manu Sporny <msporny@digitalbazaar.com>
- CC: SVG WG <www-svg@w3.org>, RDFa mailing list <public-rdf-in-xhtml-tf@w3.org>
Hi, Manu- Manu Sporny wrote (on 10/9/08 11:06 PM): > > Re-use of RDFa attributes should follow RDF in XHTML processing rules > --------------------------------------------------------------------- > > http://www.w3.org/TR/SVGMobile12/metadata.html#MetadataAttributes > """ > SVG includes several attributes that may be placed on any element, for > the use of attribute-based metadata formats. These include the 'class', > 'role', 'rel', 'rev', 'about', 'content', 'datatype', 'property', > 'resource', and 'typeof' attributes. ***SVG makes no specific > requirements about the values for these attributes, other than their > particular value data types, such as a string or a space-separated lists > of strings.*** Other specifications, such as RDFa [RDFA], Microformats > [MF] patterns, or ARIA [ARIA] ontologies, > """ > > The current text leaves far too much room for mis-use and abuse of the > RDFa attributes. It would be a shame if authors were allowed to > re-define how a non-RDFa parser may use those attributes in such a way > as to directly conflict, or even worse, create ambiguity with regard to > the current RDF in XHTML parser rules. The RDFa task force went to great > lengths to ensure that the RDFa Syntax Processing[1] rules define clear > behavior when RDFa is used in non-XHTML languages. > > Please add text clearly stating that if one re-uses the RDFa attributes > that they follow the same processing rules as outlined in the RDFa > Syntax Processing Rules[1]. > > [1] http://www.w3.org/TR/rdfa-syntax/#sec_5.5. While the SVG WG does not wish to restrict use of these attributes unduly, and hopes that they can be used productively and consistently by other formats than RDFa (such as the evil Microformats, bane of many metadaticians), we do sympathize with your desire that those attributes not be hijacked and misused. We strove to be consistent with RDFa in the way we defined the attributes themselves [1] (though the descriptions are not identical, since we felt the need to provide more context and were asked to add distinction between those attributes and others in SVG). At the same time, we are reluctant to add a normative dependency on RDFa (despite that specification's maturity) because we cannot rely upon there being multiple interoperable SVG User Agents that currently implement the RDFa processing rules. We hope this will change, spurred on by our inclusion of these attributes. Therefore, we have struck a compromise position, adding wording that recommends but does not mandate the use of the RDFa processing rules (which we can do without imposing normative requirements on UAs) [2]: [[ In order to maintain consistency and simplicity of implementation, and prevent conflict or ambiguity of use, if an author or a non-RDFa format reuses the 'about', 'content', 'datatype', 'property', 'resource', or 'typeof' attributes, it is recommended that this is done in a manner consistent with the RDFa Syntax Processing Rules [RDFA]. ]] We hope that this will satisfy your comment, but please let us know promptly either way. [1] http://dev.w3.org/SVG/profiles/1.2T/publish/struct.html#Core.attrib [2] http://dev.w3.org/SVG/profiles/1.2T/publish/metadata.html#MetadataAttributes Regards- -Doug
Received on Friday, 10 October 2008 18:05:35 UTC