Extended objects, sub-objects, and links are additional objects that can be added in any kind of model to let you design specific business needs or concepts that are not supported by PowerDesigner standard objects.
For example, you can use extended objects in a PDM to design database objects that are not natively supported. You can specify "generated files" and templates in the definition of your extended objects in order to enable their generation and reverse-engineering.
Extended objects and extended links are available in all PowerDesigner models. However, only the free model (see Using the Free Model) displays these objects by default. If you want to use extended objects and/or links in another type of model, you have to add the corresponding metaclasses and their tools to the Profile category in the model's resource file or in an extended model definition.
For information about adding extended objects, sub-objects, and links to the Profile category, see the Extending Your Models with Profiles chapter in the Customizing and Extending PowerDesigner manual.