+ const LISTEN = ActivityNamespace::ACTIVITY2 . 'Listen';
+ /**
+ * Indicates that the actor has viewed the object.
+ *
+ * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-view
+ * @var string
+ */
+ const VIEW = ActivityNamespace::ACTIVITY2 . 'View';
+
+ const O_UNFOLLOW = ActivityNamespace::OSTATUS . '/unfollow';
+ const O_UNFAVOURITE = ActivityNamespace::OSTATUS . '/unfavorite';