dataConfig DTD or schema

[Hans-Peter Stricker]

I wonder how to pass default values via <dataConfig>, e.g. like this:
<dataConfig>
   <dataSource />
   <document>
       <entity> 
           <field column="letit">BE</field>
       </entity>
   </document>
</dataConfig>

or like this:

<dataConfig>
   <dataSource />
   <document>
       <entity> 
           <field column="letit" value="BE"/>
       </entity>
   </document>
</dataConfig>

In the course of this, I did not find a DTD or Schema for <dataConfig>.

Any hint is appreciated!!