April 2010: We have recently made some improvements to the Sitemorse engine to handle XHTML+RDFa. These changes are now live and will be included in any audits run for you (including immediate tests and Snapshot).

Further reading: http://www.w3.org/TR/rdfa-syntax/

Please note that according to the above specification the 'lang' attribute has been removed. We have reflected this in our tested of pages declared as XHTML+RDFa. The attribute 'xml:lang' should be used instead to state the language code. The Sitemorse Spelling module treats the 'lang' and 'xml:lang' attributes as equal, although should the values differ 'xml:lang' will be used for the language of the tag and child elements.