XML in a Nutshell, 3rd Edition

The XSLT Namespace

All standard XSLT elements are in the http://www.w3.org/1999/XSL/Transform namespace. In this chapter, we assume that this URI is mapped to the xsl prefix using an appropriate xmlns:xsl declaration somewhere in the stylesheet. This mapping is normally declared on the root element, like this:

<xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <!-- XSLT top-level elements go here -->
</xsl:stylesheet>