query is an xs:string constrained by the language definition, http://www.w3.org/TR/rdf-sparql-query/#grammar, as "a sequence of characters in the language defined by the [SPARQL] grammar, starting with the Query production" The type for serializing query results, either as XML or RDF/XML. update is an xs:string constrained by the language definition, http://www.w3.org/2009/sparql/docs/update-1.1/Overview.xml#sec_grammar This element contains human-readable information about the fault returned by the SPARQL query processing service.