This method will create reference classes that have no attributes or operations, however these can be added as modeling continues, providing you with a view into the class, without the fear of altering the source. If you want to have access to the attributes and operations of reference classes then do not make the directories in which these classes reside 'Reference Directories'. Doing this will allow the classes to be fully reversed, and thus have all attributes and operations present on the drawing. Once you have finished reversing the system, you can manually change the necessary classes to reference classes. Depending on the size of the system, this could drastically increase processing time.
Packages can be a very powerful organizational tool.
To take advantage of this ability, you will need to be sure that a couple of items are set up properly. This will cause all packages and classes within the selected system to appear in the System Hierarchy Window. You will now need to determine how you are going to organize your system. Select an organization which suits your own tastes. You will now see the classic little yellow folder with the appropriate package name appear in your System Hierarchy Window.