As for Media, also for Documents you can manage the "lock" or "unlock" status of the document. The feature identified by a closed or open lock is used to tell the system, during export and sharing, which elements you want to keep private and which ones you want to be more easily shared.
You can manage the default status of the lock in the Settings Panel (gear symbol in the lower left corner), by choosing Documents & Media and enabling Default Status.
Artshell allows in fact, during the export and sharing phases, to decide which elements to share per single event. To simplify and quicken the process of selection, the system pre-selects the documents of every category with open lock, leaving the user the chance to select the documents with closed lock.
We suggest you to manage the state of the lock on the event documents, by choosing which one you wish to keep private in your archive (and thus you wish to seldom share) and which others you wish to show every time you export or share the record of an event.