User interface > Translation options > Types > Creating namespaces
In the professional version there is a option, to create a namespace for each unit.
If the option is enabled in C++ header files the namespaces are put in front of types from other units and in the C++ implementation files according uses clauses are inserted.
If an extended System.pas is set, the namespace for it is "d2c_system" per default, notwithstanding of the actual file name. This expression can be changed, if another name is set in the field for the system namespace. If no extended System.pas is set, the namespace for it is "System" per default and it can be changed in the same way.
You also can use the table of the substitutions of the translator, to change the namespace for a file. So it is possible, to create the same namespace for the contents of different files.