Specification of Second Argument

If you specify a second argument, it must be a node set. The XPath processor examines the first node (in the context of document order) in the node set to determine the document that this node belongs to. The XPath processor retrieves the name of the directory that contains this document and appends the relative path from the first argument to the name of the directory. This creates an absolute path, and the XPath processor retrieves the specified document.

If there is no second argument, the query must be an expression in an XSLT stylesheet. The XPath processor appends the relative path to the name of the directory that contains the XSLT stylesheet. This allows the query to examine the stylesheet itself.