First of all, sorry for my written English. I would like to know if there is a way in XML Serialization to perform serialization of objects without class_id taking into account that the objects belong to classes that derive from a Base class. My desired xml files are something like: <call> <callrequest> <number>123456789</number> </callrequest> </call> <call> <callresponse> <state>connected</state> </callresponse> </call> So I have a class "Call" that contains a pointer to an object of a class "CallType". That class is abstract, and "CallRequest" and "CallResponse" implement some methods from it. When I try to serialize the classes , although I specify that want no class_id, object_id, etc., as I have to register the classes , then class_id is always added to xml syntax: <call class_id="1"> <callrequest class_id="2"> <number>123456789</number> </callrequest> </call> <call class_id="1"> <callresponse class_id="3"> <state>connected</state> </callresponse> </call> Is there a way to serialize objects deriving from other objects without serializing class_ids ? I guess there sould be a way to specify "tag callresponse" is for deserializing class "CallResponse" ... Thanks a lot. ¿No te gusta tu dirección de correo? Consigue una que te guste de verdad - millones de direcciones de correo disponibles en Yahoo! http://es.docs.yahoo.com/mail/nueva_direccion.html