This is the format string that is applied to all summaries' text in the footer for this column. The default is "{0} = {1}" where {0} is the summary name and {1} is the value. Beware that using a formatting specific to a particular type, such as a DateTime, can cause an exception when formatting the Count or possibly a custom summary. This can be overriden on a summary setting.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, 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
