(c) 2010-2011 by Martin Hepp, mheppATcomputerDOTorg, http://www.heppnetz.de
On this page, we summarize examples of GoodRelations RDFa markup that goes beyond the basic Google and Yahoo recipes but should be accepted by parsers and validation tools.
Note: The Yahoo Validator is currently down and always reports an error "Zero Bytes received", but our testcases did all validate with the tool.
As of 2011-06-06, there is only one minor problem: If a gr:Offering is linked with a gr:BusinessEntity via gr:seeks, it should not be displayed in search results, because it represents demand, not supply. However, this is only a tiny problem, since the amount of such data is very small on a Web scale, and RDFa syntax is not likely to be the main format for such demand data anyway. We were able to find a way to make the original Yahoo recipe from 2008 validate with Google's tool (even review data). All testcases show that it is possible to create mark-up that validates with both Yahoo and Google, and that adding richer GoodRelations patterns, e.g. by using the VSO or TIO extensions for cars or tickets, does not conflict with being Google- and Yahoo-compatible.