The following is a redline version of the proposed changes:

<wsdl:definitions targetNamespace='http://schemas.xmlsoap.org/ws/2004/09/mex'
                  xmlns:tns='http://schemas.xmlsoap.org/ws/2004/09/mex'
                  xmlns:wsa10='http://www.w3.org/2005/08/addressing'
                  xmlns:wsa04='http://schemas.xmlsoap.org/ws/2004/08/addressing'
                  xmlns:wsam="http://www.w3.org/2007/05/addressing/metadata
"
                  xmlns:wsdl='http://schemas.xmlsoap.org/wsdl/'
                  xmlns:xs='http://www.w3.org/2001/XMLSchema'>
  <wsdl:types>
    <xs:schema targetNamespace='http://schemas.xmlsoap.org/ws/2004/09/mex'>
      <xs:include schemaLocation='metadataexchange.xsd'/>
    </xs:schema>
  </wsdl:types>

  <wsdl:message name='GetMetadataMsg'>
    <wsdl:part name='body' element='tns:GetMetadata'/>
  </wsdl:message>
  <wsdl:message name='GetMetadataResponseMsg'>
    <wsdl:part name='body' element='tns:Metadata'/>
  </wsdl:message>

  <wsdl:portType name='MetadataExchange'>
    <wsdl:operation name='GetMetadata'>
      <wsdl:input message='tns:GetMetadataMsg'
wsa10:Action=
'http://schemas.xmlsoap.org/ws/2004/09/mex/GetMetadata/Request'
wsa04:Action=
'http://schemas.xmlsoap.org/ws/2004/09/mex/GetMetadata/Request'

                  wsam:Action="http://www.w3.org/ws/XXXX/XX/mex/GetMetadata/Request"/>
      <wsdl:output message='tns:GetMetadataResponseMsg'
wsa10:Action=
'http://schemas.xmlsoap.org/ws/2004/09/mex/GetMetadata/Response'
wsa04:Action=
'http://schemas.xmlsoap.org/ws/2004/09/mex/GetMetadata/Response'

                   wsam:Action="http://www.w3.org/ws/XXXX/XX/mex/GetMetadata/Response"/>
    </wsdl:operation>
  </wsdl:portType>

</wsdl:definitions>

As you can see, I've elected to use the wsam:Action attribute to explicitly define the [action] properties of the GetMetadataMsg and GetMetadataResponseMsg messages.

This fulfills my obligations under ACTION-4.

- gp