message lookupUserRequest
parts 
parameters
element resolver:lookupUser
used by 
Operation lookupUser in PortType EntityResolverService
source  
<wsdl:message name="lookupUserRequest">
  <wsdl:part name="parameters" element="resolver:lookupUser"/>
</wsdl:message>

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