message listCategoriesRequest
parts 
parameters
element business:listCategories
used by 
Operation listCategories in PortType BusinessService
source 
<wsdl:message name="listCategoriesRequest">
  <wsdl:part name="parameters" element="business:listCategories"/>
</wsdl:message>

WSDL documentation generated by XMLSpy WSDL Editor http://www.altova.com/xmlspy