Hi Keith,

This might be totally useless, but this is the way I use relationships between XML documents:

1) Consider the two XML documents bellow (Orders and Products):

--- Orders ---

<?xml-stylesheet type="text/xsl" href="OrdersProducts.xsl" ?>
<Orders> 

  <Order id="1"> 
    <Item id="1"> 
      <Qty>10</Qty> 
    </Item> 
    <Item id="2"> 
      <Qty>1</Qty> 
    </Item> 
  </Order> 

  <Order id="2"> 
    <Item id="1"> 
      <Qty>1</Qty> 
    </Item> 
  </Order> 

  <Order id="2"> 
    <Item id="2"> 
      <Qty>1</Qty> 
    </Item> 
  </Order> 

</Orders> 

--- Products ---

<Products> 
  <Product id="1"> 
    <Description>Produto One</Description> 
  </Product> 
  <Product id="2"> 
    <Description>Produto Two</Description> 
  </Product> 
</Products> 

Bu using the xsl:document() function we are able to reference nodes from an external XML document. The followinf XSLT document shows how we could present a report displaying the orders and related items:

<?xml version='1.0'?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

   <xsl:template match="/">
      <xsl:apply-templates select="//Orders"/>
   </xsl:template>

  <xsl:template match="Order">
      <b>Pedido: <xsl:value-of select="@id" /> </b> <br/>
      <xsl:apply-templates select="Item"/>
  </xsl:template>

  <xsl:template match="Item">
      <xsl:variable name="IDProduto" select="@id" />
      <xsl:value-of select="$IDProduto" /> <br/>
      <xsl:value-of select="document('Products.Xml')/Products/Product[@id=$IDProduto]/Description" /> <br/>
  </xsl:template>

</xsl:stylesheet>

HTH.