When the width of the root visual that contains the ribbon is below the AutoHideHorizontalThreshold or the height is below the AutoHideVerticalThreshold, the contents of the ribbon (including RibbonGroups, RibbonTabItems, QuickAccessToolbar and ApplicationMenu) will be hidden.
Note: This property is only used if the AutoHideEnabled property has been set to true. AutoHideEnabled defaults to false.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2