a secretary's telephone being able to answer the boss' extensions. Privacy prevents someone else who has the same line or extension from inadvertently cutting in on your conversation. If you want to let him in, you may do SO if you have a privacy release button. Not all telephone systems are automatically equipped with the privacy feature. Some systems have automatic privacy, while others require that a separate button on each telephone be activated to ensure privacy. A separate button called privacy release can let a person The Telecom Handbook . 47 THE PBX at another telephone in on a conversation if you want him to join you or listen in. RELEASE Most telephones working with a PBX have a release button. When you press it, the effect is the same as if you hung up the receiver and then lifted it up again. Pressing release disconnects a completed call and gives you back the dial tone to place an- other call. Do NOT DISTURB When the "Do Not Disturb" button is depressed, on most sys- items, you will not receive internal calls or intercom calls. This button often overlaps in function with a button that, when de- pressed, sends callers directly to your Voice Mail box without ringing your telephone. CALL PARK This enables you to ask a caller to wait, place the call in limbo in a numbered "parking place" in the system (the call will no longer appear on your telephone when parked). You can go to any other telephone on the system and retrieve the parked call by dialing the parking place number. This is also used by switchboard attendants who park calls and then an- nounce over the office paging system, "Tom Taylor, dial 23." 23 is the parking code. CALL WAITING OR CAMP-ON If you are on a call and do not have a second extension, a second call may still get though to you using Call Waiting (also called Camp-On in older systems). You will hear a tone indicat- ing a second incoming call and may press a button or the switch- hook to answer the second call without losing the call you're already on. The first caller cannot hear 