The NOTIFICATION_RPC structure associates the NOTIFICATION_DATA_RPC structure with the notify key that was passed as a parameter to ApiAddNotifyV2 (section 3.1.4.2.137).
typedef struct _NOTIFICATION_RPC {
DWORD_PTR dwNotifyKey;
NOTIFICATION_DATA_RPC NotificationData;
} NOTIFICATION_RPC,
*PNOTIFICATION_RPC;
dwNotifyKey: A 32-bit value provided by the client.
NotificationData: A NOTIFICATION_DATA_RPC structure as defined in section 2.2.3.23.