An extended model definition allows you to expand object definitions and complement the generation targets and commands. Extended model definitions are created and saved in files with the XEM extension. You can create or attach one or several extended model definitions to a model.
When you create a new XML model, or when you reverse engineer into a new XML model, you can select one or several extended model definitions and attach them to the model from the New dialog box.
For more information on extended model definitions, see "Extended Model Definitions" in the Resource Files and the Public Metamodel chapter of the Customizing and Extending PowerDesigner manual.