Those are defined in the WSDL.

In vim.wsdl (from the SDK 4.1 package):

<operation name="RetrieveProperties">
         <input message="vim25:RetrievePropertiesRequestMsg"/>
         <output message="vim25:RetrievePropertiesResponseMsg"></output>
         <fault name="InvalidPropertyFault" message="vim25:InvalidPropertyFaultMsg"></fault>
         <fault name="RuntimeFault" message="vim25:RuntimeFaultFaultMsg"></fault>
</operation>

<operation name="RetrievePropertiesEx">
         <input message="vim25:RetrievePropertiesExRequestMsg"/>
         <output message="vim25:RetrievePropertiesExResponseMsg"></output>
         <fault name="InvalidPropertyFault" message="vim25:InvalidPropertyFaultMsg"></fault>
         <fault name="RuntimeFault" message="vim25:RuntimeFaultFaultMsg"></fault>
 </operation>

Though you're right, the ESX 4.1 host WSDL is missing those values. However, I used a quick perl script that calls RetrievePropertiesEx to test it. No soap faults, though I found you had to add a RetrieveOptions object as the options argument to the call. The maxObject property of RetrieveOptions is optional, but it still expects the option object value in the serialized XML.

Also note the return type has changed for the RetrievePropertiesEx call.

I also tested using just a plain RetrieveProperties call, no issues there either.

Looks like you just found a bug with the wsdl files on the web server root, but I suspect your error is related to your code not a missing implementation of the soap call. Particularly when you mentioned you're using PHP5 and in the past I've pointed out some of the issues with XML serialization with vanilla soap implementations not aware of the VMware SDK data model (Python suds, PHP nusoap).