Hello Gerrit, GB> is it possible to suppress the in the xml-output generated GB> attributes for object types (class_id, tracking_level and version)? Sure, it is possible. But at the expense of tracking and versioning of course. You should tell explicitly to the serialization library that your classes have to have no versioning and tracking information. It can be done by using special traits classes. To make long story short, just add two following macros for every your class that has to be serialized without additional info: BOOST_CLASS_IMPLEMENTATION(YourClassName, boost::serialization::object_serializable); BOOST_CLASS_TRACKING(YourClassName, boost::serialization::track_never) Regards. Slava. -- -- Vyacheslav E. Andrejev -- System Architect, Optech International, Inc. -- E-mail: mortituris@mail.ru