DOCBOOK-APPS: section numbering depth

Hello,

is there parameter to limit the depth of section numbering in the xsl 
stylesheets to a certain section level (using docbook-xsl-1.41, saxon 
6.4.3, fop-0.19)?

To limit the section depth listed in the toc I included <xsl:param 
name="toc.section.depth" select="3"/> to my param.xsl customization 
stylesheet which has no affect at all? I'm not that familiar yet with xsl 
and the stylesheets - is there another attribute I could set?



Ciao
   jENs