isCustom
isCustom() method
Shows if this property does not belong to the predefined properties list in the specification: https://msdn.microsoft.com/en-us/library/dd949052(v=office.15).aspx
Returns
boolean
Shows if this property does not belong to the predefined properties list in the specification: https://msdn.microsoft.com/en-us/library/dd949052(v=office.15).aspx
boolean