This property is typically used when the controls the System.Windows.Forms.Splitter control is docked to are displayed with a specific border style and you want the System.Windows.Forms.Splitter control to match their display style. For example, if you have a System.Windows.Forms.TreeView and a System.Windows.Forms.ListView control that the System.Windows.Forms.Splitter control will be docked to that you want to display without any borders, you can set the Splitter.BorderStyle property to BorderStyle.None.