Pre-1.0 working drafts of XSLT used text/xsl in their embedding examples, and this type was implemented and continued to be promoted by Microsoft in Internet Explorer and MSXML circa 2012. It is also widely recognized in the xml-stylesheet processing instruction by other browsers. In practice, therefore, users wanting to control transformation in the browser using this processing instruction were obliged to use this unregistered media type.
Pre-10 working drafts of XSLT used text/xsl in their embedding examples, and this type was implemented and continued to be promoted by Microsoft in Internet Explorer and MSXML circa 2012. It is also widely recognized in the xml-stylesheet processing instruction by other browsers. In practice, therefore, users wanting to control transformation in the browser using this processing instruction were obliged to use this unregistered media type.