By default, the group's tooltip is empty. If the ToolTip property is empty the control displays no tooltip when the cursor hovers the group's caption. The ToolTip shows up when the cursor hovers the group's caption. Use the ToolTipDelay to specify the time in ms that passes before the ToolTip appears. In this case no tooltip is displayed when cursor is over the group's caption. Use the ToolTipWidth property to specify the width of the tooltip window. The ToolTip supports built-in HTML format as described here.