number format="001. "
File: Data.xml <colors> <color>red</color> <color>green</color> <color>blue</color> <color>yellow</color> <color>purple</color> <color>brown</color> <color>orange</color> <color>pink</color> <color>black</color> <color>white</color> <color>gray</color> </colors> File: Transform.xslt <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:output method="xml" omit-xml-declaration="yes" indent="no" /> <xsl:template match="color"> <xsl:number format="001. " /> <xsl:apply-templates /> </xsl:template> </xsl:stylesheet> Output: 001. red 002. green 003. blue 004. yellow 005. purple 006. brown 007. orange 008. pink 009. black 010. white 011. gray