I tried a couple of things (looked online and such), but ended up
getting more confused. I want insert <xxx> before the <afi> element.
There are many elements prior to the element closing. This sounds
simple, but newbie-ness is getting in the way.

before:
<afi><fault fcode="xx-xx-xxx"/><describe><fdesc>xxx</fdesc></describe></afi>

after:
<afi><xxx><fault
fcode="xx-xx-xxx"/><describe><fdesc>xxx</fdesc></describe><xxx></afi>

  <xsl:template match="afi">
    <xsl:copy>
      <xxx>
        <xsl:apply-templates/>
      </xxx>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="@* | node()">
    <xsl:copy>
      <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
  </xsl:template>

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/