how to import in oracle 10G a dump taken from a 11G database

The main problem : you want to use datapump ( expdp/impdp ) in order to move data between databases ( from 11G to 10G ).

In the default mode, this is not possible ( an 11G dump will not be recognized to a 10G database )

Solution: expdp directory=... schemas=.... version=10.2 ( this command should be performed on 11G database)