#ifdef EXPERIMENTAL_TPDA
int tpda_defer_errno = 0;
-uschar *tpda_event = NULL;
-uschar *tpda_data = NULL;
+uschar *tpda_event = NULL; /* event name */
+uschar *tpda_data = NULL; /* auxilary data for event */
+uschar *delivery_event_action = NULL; /* expansion for delivery events */
#endif
transport_instance *transports = NULL;