When used by the Infragistics.Controls.Grids.XamSpreadsheet to display the input message for the active cell, this will be initialized to the Description of the associated DataValidationRule whose input message is being displayed.
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