When the top-level window of an application that is a member of an Application Group is the target of a MapWindow or ConfigureWindow request, if there is an Application Group Leader then MapRequest and ConfigureRequest events are automatically delivered to it, otherwise the core protocol semantics apply, i.e. they are delivered to the client, if any, that has SubstructureRedirect set in its root-window event mask, e.g. the window manager.
 | Note: The Application Group Leader must not select SubstructuRedirect events on a root window as doing so would result in a core protocol error; only one client is permitted to do so, and that is usually the window manager. |
When a MapWindow request is received for a window whose override-redirect attribut is set to False and whose parent is the root window and the window belongs to an application that is in an application group and there is an application group leader for the group, then this event is delivered to the Application Group Leader with the parent field in the event set to the AppGroup ID. Otherwise the core protocol semantics apply.
When a ConfigureWindow request is received for a window whose override-redirect attribut is set to False and whose parent is the root window and the window belongs to an application that is in an application group and there is an application group leader for the group, then this event is delivered to the Application Group Leader with the parent field in the event set to the AppGroup ID. Otherwise the core protocol semantics apply.