To override the Content-type in your clients, use the HTTP Accept Header, append  the .xml suffix or  ?format=xml
        
        HTTP + XML
         The following are sample HTTP requests and responses. 
            The placeholders shown need to be replaced with actual values.
POST /News_Subscribe HTTP/1.1 
Host: wbs.e-teleport.ru 
Accept: application/xml
Content-Type: application/xml
Content-Length: length
<News_Subscribe xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/TeleportService.ServiceModel">
  <Contact>String</Contact>
</News_Subscribe>
 
HTTP/1.1 200 OK
Content-Type: application/xml
Content-Length: length
<News_SubscribeResponse xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/TeleportService.ServiceModel">
  <AllowPrivateNews>false</AllowPrivateNews>
  <ErrCode>0</ErrCode>
</News_SubscribeResponse>