DA14531 Bluetooth and Xamarin.

public class GattIdentifiers
    {
        public static Guid UartGattServiceId = Guid.Parse("866d3b04-e674-40dc-9c05-b7f91bec6e83");
        public static Guid UartGattCharacteristicSendId = Guid.Parse("914f8fb9-e8cd-411d-b7d1-14594de45425");
        public static Guid UartGattCharacteristicReceiveId = Guid.Parse("3bb535aa-50b2-4fbe-aa09-6b06dc59a404");
        public static Guid SpecialNotificationDescriptorId = Guid.Parse("e2048b39-d4f9-4a45-9f25-1856c10d5639");

        public static Guid DSPS_SERVICE_UUID = Guid.Parse("0783b03e-8535-b5a0-7140-a304d2495cb7");
        public static Guid DSPS_SERVER_TX_UUID = Guid.Parse("0783b03e-8535-b5a0-7140-a304d2495cba");
        public static Guid DSPS_SERVER_RX_UUID = Guid.Parse("0783b03e-8535-b5a0-7140-a304d2495cb8");
        public static Guid DSPS_FLOW_CONTROL_UUID = Guid.Parse("0783b03e-8535-b5a0-7140-a304d2495cb9");   
    }