Specifies that an attribute of type java.util.List is semantically a bag, that is, that the order of the list elements is not significant, and should not be persistent.

This annotation is not necessary, and has no effect, unless the configuration property hibernate.mapping.default_list_semantics is set to org.hibernate.metamodel.CollectionClassification#LIST. However, its use is still encouraged, since the explicit annotation serves as useful documentation.