In this ASP.NET AJAX Chart demo, you can see how to add Notes for the Min and Max values of LineSeries.
        To do that you need to set the Series -> DataNoteTextField to a valid field of the chart series. Within the NotesApperance inner tag you
        can specify the Note's Icon, Line and Label apperance.
        
        Sample declaration:
        
            <NotesAppearance Position="Bottom">
                <Icon Type="Circle" Size="8" BackgroundColor="Transparent" Visible="true">
                    <Border Width="1" Color="Black" />
                </Icon>
                <Label Position="Outside" DataFormatString="{0} titles">
                    <Border DashType="Solid" Color="Black" Width="1" />
                    <TextStyle Bold="false" Italic="false" FontSize="12" />
                </Label>
                <Line DashType="Solid" Length="10" Width="1" Color="Black" />
            </NotesAppearance>