From Tracker Software PDF SDK
The event is fired before the document will be saved. The IEvent interface should be cast to the IPXV_DocSaveEvent interface. This event is used in pair with the After Save Event.
|Handled||VARIANT_BOOL||Specifies whether the event was handled. Marking the event as handled will cause the event sender to look at the event`s result and act accordingly based on the event type.|
|Result||PARAM_T||Specifies the result that will be used by the event sender when the event is marked as Handled. If the Result is not E_NOTIMPL then the document saving will no longer be continued.|