Message Header

<http:MessageHeader>
  <http:fieldName rdf:resource="http://www.w3.org/2006/http-header#content-type"/>
  <http:fieldValue>
    <http:HeaderElement>
      <http:elementName>application/xhtml+xml</http:elementName>
      <http:param>
        <http:Param>
          <http:paramName>charset</http:paramName>
          <http:paramValue>utf-8</http:paramValue>
        </http:Param>
      </http:param>
    </http:HeaderElement>
  </http:fieldValue>
</http:MessageHeader>