<property_sheet_list>
 <portal_type id="Open Sale Order">
  <item>VifibOpenSaleOrderConstraint</item>
 </portal_type>
 <portal_type id="Open Sale Order Line">
  <item>VifibOpenSaleOrderLineConstraint</item>
 </portal_type>
 <portal_type id="System Preference">
  <item>VifibSystemPreference</item>
 </portal_type>
</property_sheet_list>