Branching and Control Elements(Chapter 5 of XSLT 2nd Edition)

    To invoke a template by name, two things have to happen:
    • The template you want to invoke has to have a name.
    • You use the <xsl:call-template> element to invoke the named template.

    The XSLT <xsl:template> element has a mode attribute that lets you process the same set of nodes several times.

    XSLT 2.0 adds a required attribute to the <xsl:param> element. Valid values are yes and no, as you’d expect. If a parameter is required, the <xsl:param> element must not have a select attribute.