Is it not possible to inject mutually exclusive instances of the same type? At first thought, the @Role solution seems awkward. I have been thinking about this same type of scenario, for a project still in the early stages of thought. I thought I might try using a discriminator column, to provide different subtypes. I've used this in Hibernate and another ORM api but have not tried it with JPA/EJB3 yet. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4052250#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...