Modes allow an element to be processed multiple times, each time producing a different result. Both xsl:template and xsl:apply-templates have an optional mode attribute. If xsl:template does not have a match attribute it must not have a mode attribute. If an xsl:apply-templates element has a mode attribute, then it applies only to those template rules from xsl:template elements that have a mode attribute with the same value; if an xsl:apply-templates element does not have a mode attribute, then it applies only to those template rules from xsl:template elements that do not have a mode attribute.