This is the first draft version of the Query schema for querying a Resource Registry. See: http://www.ivoa.net/xml/VOResource/v0.9 The structure of this schema is much like a very basic criteria or predeicate to most popular query languages. Deals with a particular criteria to perform on a Resource Registry. This section looks very much like most query languanges except it uses an XPath to represent on what you querying against.