The Persistence specs (chapter 2.1.6) say as follows:
------------------------------------ �If a persistent field or property other than a relationship property is not annotated with one of the mapping Annotations (or equivalent mapping information is not specified in the XML descriptor), the following default mapping rules are applied in order
If the type is a class that is annotated with the Embeddable annotation, it is mapped in the same way as if the field or property were annotated with the Embedded annotation. ---------------------------------------- Does this imply that @Embedded annotation is not mandatory.