changing font size of element <code/>

Hello DocBook-users,

I hope this will be the last question so far :-)

I changed monospace fonts to 8.5pt for listings and now I am searching 
for a possibility to do the same for the inline element <code/>. 
Actually the font size is 10pt, same like body text.

Are there any possibilities to do font size changing using a custom 
layer? If not, where could I change the font size especialy for <code/>?

I tried

    <xsl:template match="code">
        <fo:inline font-size="8.5pt">
            <xsl:apply-templates/>
        </fo:inline>
    </xsl:template>

but nothing happend.


This should be the last task :-)

Thanks in advance for suggestions,
Andreas