As a last part, we want to provide explicit data typing. The following envelope is in a format known as RPC/Encoded.

SOAP Envelope
<SOAP-ENV:Envelope
  xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
  xmlns:ns4="http://soapinterop.org/"
  SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
  
  <SOAP-ENV:Body>

    <method:echoString>
      <inputString xsi:type="xsd:string">hello world!</inputString>
    </method:echoString>
    
  </SOAP-ENV:Body>
  
</SOAP-ENV:Envelope>
Data typing does not necessarily have to happen in the SOAP message. XML Schema and WSDL can provide that information, or the client can simply dynamicaly handle the data types as it sees fit.