[ComImport(),
    Guid("00021500-0000-0000-C000-000000000046"),
    InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    interface IQueryInfo
    {
        [PreserveSig]
        int GetInfoTip(
            int dwFlags,
            [MarshalAs( UnmanagedType.LPWStr )] out string ppwszTip );

        [PreserveSig]
        int GetInfoFlags( out int pdwFlags );
    }

    // ppwszTip will be freed by marshler using CoTaskMemFree()