message listAttributeNamesRequest
parts 
parameters
element dir:listAttributeNames
used by 
Operation listAttributeNames in PortType DirectoryService
source  
<wsdl:message name="listAttributeNamesRequest">
  <wsdl:part name="parameters" element="dir:listAttributeNames"/>
</wsdl:message>

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