Preceding-Sibling | The Easy Way

Keeping on track with my previous post regarding the preceding-sibling approach to getting unique values with XSL, I prefer to not have to do the Muench method whenever possible. I like to keep it simple. Here is a really simple way to get a unique or distinct list of categories and sub-categories from an xml file:

<xsl:for-each select="item">
 <xsl:variable name="thisNodeCategory" select="Category"/>
 <xsl:if test="not(preceding-sibling::item[Category=$thisNodeCategory])">
  <span class="Category">
   <a href="">
    <xsl:value-of select="Category" />
   </a>
  </span>
  <br/>
 </xsl:if>
 <xsl:if test="SubCategory > ''">
  <span class="subCategory">
   - <a href="">
    <xsl:value-of select="SubCategory" />subcategory
   </a>
  </span>
  <br/>
 </xsl:if>
</xsl:for-each>