You can limit a proxy’s access to individual items in your Mailbox or Calendar by marking items Private.
When you mark an item Private, you prevent unauthorized proxies from opening it. Proxies cannot access items marked Private unless you give them those rights in your Access List.
If you mark an item Private when you send it, neither your proxies nor the recipient’s proxies can open the item without rights. If you mark an item Private when you receive it, it cannot be read by your unauthorized proxies, but it can be read by the sender’s proxies. Appointments marked Private display in Busy Search according to the status you selected when you accepted the appointment.
In an open item, click> .
In your Calendar, click an item in the Appointments, Reminder Notes, or Task List, then click> .
It is also possible to set up a rule to automatically mark an item as Private when it is moved into a certain folder or calendars. For example, if you want to keep all items in a sub-calendar private, you can assign a rule to mark all items in that calendar as Private. For more information on creating a rule, see Creating a Rule.