Hi Alexander,
Privacy - Applies to "Shared Lines" only;
Users press this button to activate/deactivate privacy.
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/4_1_3/ccmsys/a08ipph.html#wpxref13210
Privacy
With Privacy, administrators can enable or disable the capability of users with phones that share the same line (DN) to view call status and to barge the call. Administrators enable or disable Privacy for each phone or for all phones in the cluster.
By default, the system enables Privacy for all phones in the cluster. To enable all phones with Privacy, leave the clusterwide service parameter set to True and leave the phone privacy setting set to default.
To configure certain phones with access to Privacy, administrators perform the following steps to enable or disable Privacy:
•Set a service parameter.
•Set the phone privacy setting to On.
•Add Privacy button to phone button template.
•Add the phone button template that has Privacy button to each device.
When the device that is configured for privacy registers with Cisco Unified Communications Manager, the feature button on the phone that is configured with Privacy gets labeled, and the status shows through an icon. If the button has a lamp, it lights.
When the phone receives an incoming call, the user makes the call private (so the call information does not display on the shared line) by pressing the Privacy feature button. The Privacy feature button toggles between on and off.
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/6_0_1/ccmfeat/fsbarge.html#wp1033217
So, if your phone has DN 8500 on it and so does your Secretary's phone, when the Private button is pressed before making a personal call, she will not see the call details or be able to Barge the call :)
Hope this helps!
Rob
