Heavily refactored, including multiple calendars per user and recurring events. Not in an installable state yet, though

dav/SabreDAV/lib/Sabre/CalDAV/Notifications/ICollection.php

@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * This node represents a list of notifications.
+ *
+ * It provides no additional functionality, but you must implement this
+ * interface to allow the Notifications plugin to mark the collection
+ * as a notifications collection.
+ *
+ * This collection should only return Sabre_CalDAV_Notifications_INode nodes as
+ * its children.
+ *
+ * @package Sabre
+ * @subpackage CalDAV
+ * @copyright Copyright (C) 2007-2012 Rooftop Solutions. All rights reserved.
+ * @author Evert Pot (http://www.rooftopsolutions.nl/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+interface Sabre_CalDAV_Notifications_ICollection extends Sabre_DAV_ICollection {
+
+
+}