* the events.
* @event_types: an #AtspiDeviceEventMask mask indicating which
* types of key events are requested (%ATSPI_KEY_PRESSED, etc.).
- * @filter: Unused parameter.
+ * @filter: (allow-none): Unused parameter.
* @error: (allow-none): a pointer to a %NULL #GError pointer, or %NULL
*
* Registers a listener for device events, for instance button events.
* atspi_deregister_device_event_listener:
* @listener: a pointer to the #AtspiDeviceListener for which
* device events are requested.
- * @filter: Unused parameter.
+ * @filter: (allow-none): Unused parameter.
* @error: (allow-none): a pointer to a %NULL #GError pointer, or %NULL
*
* Removes a device event listener from the registry's listener queue,