Hi, Can I suggest adding another example to: http://www.boost.org/libs/serialization/doc/special.html#objecttracking I had this code: void mycallback(const BigClass &BC){ const SomeData *d=BC.get_data(); ... archive & BOOST_SERIALIZATION_NVP(d); } My archive was smaller than intended and I discovered that the data only got saved the first time. XML version showed me it was using: object_id_reference. It turns out the fix was to dereference the pointer: archive & BOOST_SERIALIZATION_NVP(*d); That is an easy to write bug; I cannot see how the serialization library can catch it, so all I can think of is to make people aware of it in the docs. Also please mention "object_id_reference" in the objecttracking section of the docs, as that was the first thing I googled on and it got no useful hits. Darren