diazo_fallback_parameters_rules.xml

<?xml version="1.0" encoding="UTF-8"?>
<rules xmlns="http://namespaces.plone.org/diazo"
 xmlns:css="http://namespaces.plone.org/diazo/css"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:xi="http://www.w3.org/2001/XInclude">

 <!-- The empty params defined here will be overridden by your manifest.cfg. -->
 <xsl:param name="portal_url"></xsl:param>
 <xsl:param name="header">normal</xsl:param>
 <xsl:param name="email">[email protected]</xsl:param>

 <!-- Now add your rules ... -->
</rules>