The class identifies data to append to a single property of an item during an UpdateItem operation.
Assembly: EWS (in EWS.dll)
Only certain properties support append operations. An attempt to append to a property that does not support appending will result in an error.
For update operations, only one property can be modified within a single request. That single property must be referenced in the Path element. The Item element in the derived classes can then only hold a single property that is in agreement with the single Path element.