Best way to mark up general conditions of sale [german: AGB]

Hi,

i want to markup some legal documents with simplified docbook.
I have a text with lots of paragraphs which are nested like this:

Example: 
-------
1. Geltungsbereich: Diese Allgemeinen Gesch輎tsbedingungen [...]
2. Preise:
2.1. Die Berechnung erfolgt aufrgund der [...]
2.2. Die Preise gelten jeweils [...] 
3. Eigentumsvorbehalt: Die Ware bleibt [...]
4. Haftung: [...]
-------

some have titles (level1), some don't (level2).

I found some docbook markuped GPL which uses sections. 
My problem is that nested sections always need a title. 
so i got a problem on level2. 

but nested orderedlists dont allow titles on listitems, only on the 
list itself. 

What is the best way to markup those documents?

At the moment i use formalpara in listitem like the following markup. 
Are there better ways to markup legal documents.

<orderedlist>
  <listitem>
    <formalpara>
      <title>Geltungsbereich</title>
      <para>...</para>
    </formalpara>
  </listitem>
  <listitem>
    <formalpara>
      <title>Preise</title>
      <para>
        <orderedlist inheritnum="inherit">
          <listitem>
            <para>...</para>
          </listitem>
          <listitem>
            <para>...</para>
          </listitem>
      </para>
    </orderedlist>
  </listitem>
  [...]
</orderedlist>
   
kind regars,
janning