We have a collection of core EJB 3 entities that support our core product framework. This framework includes entities that are commonly needed by an application and include such things as addresses, email, as well as product specific entities. This is defined as a separate persistence unit that is built separate from any application, has it's own test cases, and it's own cvs module.
As we develop a new application which in turn has it's own application specific EJB 3 entities how can we reference and define ORM relationships between the core framework entities as well as application specific entities? Can we just define a second persistence unit within the application's persistence.xml file that references the core framework?