If the annotation@Documented is present on the declaration of an annotation interfaceA, then any@A annotation on an element is considered part of the element's public contract. In more detail, when an annotation interfaceA is annotated withDocumented, the presence and value ofA annotations are a part of the public contract of the elementsA annotates. Conversely, if an annotation interfaceB isnot annotated withDocumented, the presence and value ofB annotations arenot part of the public contract of the elementsB annotates. Concretely, if an annotation interface is annotated withDocumented, by default a tool like javadoc will display annotations of that interface in its output while annotations of annotation interfaces withoutDocumented will not be displayed.