The Virtuoso XSLT processor recognizes and verifies the <xsl:output> tag. The only <xsl:output> attributes that are used are the method, encoding, omit-xml-declaration, media-type, doctype-public doctype-system and indent. The processor output is created in the character set that is in effect for the client or the one specified by encoding.

The SQL function xml_tree_doc_media_type() returns the media type in effect for the result of the xslt() function based on the xsl:output media-type and method attributes of the stylesheet applied. This method is also used for producing FOR XML AUTO WebDAV resources for HTTP reply generation.