Font familiy of some automatically generated index-entries

Hello list,

I just wonder why when use an indexterm like

<indexterm>
   <primary>
     <function>printf()</function>
   </primary>
</indexterm>

the word "printf()" does not appear in fixed font in the index. It 
appears there in proportional font like the normal flow of text, neither 
in HTML, nor in PDF output (using XSLT-stylesheets 1.62.4)

What can I do to have all my programming constructs like <function>s, 
<methodname>s, <class>es and so on rendered in fixed font in the index?

Joachim

-- 
Joachim Ziegler                       Stuhlsatzenhausweg 85
Max-Planck-Institut für Informatik    66123 Saarbrücken, Germany
Email:           Tel.: (+49) 0681 9325-127