The result format. This can be any of the Virtuoso supported formats:
For SPARQL select binding results:
auto - Automatic selection
HTML - text/html
application/vnd.ms-excel - Spreadsheet
application/sparql-results+xml - XML
application/sparql-results+json - JSON
application/javascript - Javascript
text/rdf+n3 - N3/Turtle
application/rdf+xml - RDF/XML
text/plain - N-Triples
text/csv - CSV
text/tab-separated-values - TSV
For construct or describe results:
text/rdf+n3 - N3/Turtle
application/rdf+json - RDF/JSON
application/rdf+xml - RDF/XML
text/plain - N-Triples
application/xhtml+xml - XHTML+RDFa
application/atom+xml - ATOM+XML
application/odata+json - ODATA/JSON
application/x-json+ld - JSON-LD
text/x-html+ul - HTML (list)
text/x-html+tr - HTML (table)
text/html - HTML+Microdata
application/microdata+json - Microdata/JSON
text/csv - CSV
text/tab-separated-values Tab-separated values
application/x-trig - TriG
application/x-nice-turtle - Pretty-printed Turtle (slow!)