+
+// This URL is used to save the state of the view controller. Return
+// nil if you cannot or should not save the URL for this page.
+- (NSURL *) navigationURL;
+
+// By default, this delegate is unused. However, it's provided here in case
+// you need some kind of delegate in a subclass.
+- (void) setDelegate:(id)delegate;
+- (id) delegate;
+
+// Override this in subclasses if you manage the "has seen first load" state yourself.
+- (BOOL) hasLoaded;
+
+// This is called when the view managed by the view controller is released.
+// That is not always when the controller itself is released: it also can
+// happen when more memory is needed by the system or whenever the controller
+// just happens not to be visible.