[Level] 0 [Preserves] 
Preserves the XPath data model Level 0 defines the class of candidates that preserve the XPath 1.0 data model. Such preservation includes the root node, elements, text nodes, attributes (not including namespace declarations), namespaces, processing instructions and comments. Unexpanded entities, the document type declaration and the internal subset are not preserved. This level corresponds to a common denominator in XML processing, it is equivalent to the SOAP XML subset with the addition of processing instructions and comments.