Is XSLT not an XML document itself?

I’m confused by your comment. My XSLT stylesheets are like this:

``` <?xml version="1.0"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> ```

Yes it is, I was asking why it needed to be. Sorry if that wasn't clear.