URL or file name of the Xsl transformation to apply to the source.
Used if an XSLT is not specified directly using the Xslt element.
The referenced XSLT can use the semplified XSL syntax
Use the special URL:
self://localhost/do.ashx?cmd=config&name=xsl_XXXXX
to get the XSL from the global configuration named 'xsl_XXXXX'