If SummaryPosition property is set to UseSummaryPositionField, then the summary will be positioned under this field inside the summary record. If this property is not set, it will be positioned under the field specified by SourceFieldName.
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