User interface > Translation options > Input options > Unit scope names
A list of unit scope names, which help to find used file, can be entered in the following dialog, which can be opened at the Input-Options.
These identifiers are prefixes in dotted unit names. E.g. System is the prefix of the unit System.Classes whose file is System.Classes.pas. If a unit uses a file it suffices to indicate the name without the prefix, if the prefix is in the list of Unit scope names. At the example above:
uses Classes;
instead of
uses System.Classes;
So, if System is in the list of unit scope names, Delphi2Cpp nevertheless will lookup the file System.Classes.pas.