font-size for simplelist ?

Hi there,

  Does anyone knows how to change the font size of all element in a
simplelist ? I tried a naive approach:

<xsl:attribute-set name="simplelist.properties">
  <xsl:attribute name="font-size">
    <xsl:choose>
      <xsl:when test="@role= 'small">10pt</xsl:when>
      <xsl:otherwise>inherit</xsl:otherwise>
    </xsl:choose>
</xsl:attribute>
</xsl:attribute-set>

with no luck.

I cannot find any references neither on:

http://docbook.sourceforge.net/release/xsl/1.76.1/doc/fo/lists.html

nor on:

http://www.sagehill.net/docbookxsl/SimpleList.html

Thanks !

-- 
Mathieu