AT&T MERLIN LEGEND Release 4.0 Feature Reference page 234

Feature Reference
Considerations and Constraints
Do Not Disturb must be programmed onto an available button.
If you turn on Do Not Disturb while receiving a call (either ringing or
voice-announced), the caller continues to hear ringback (or a voice-announced
caller may stay on the line), but you do not hear ringing. The Do Not Disturb
feature remains on.
When the principal's Do Not Disturb is turned on, his or her calls ring at other
telephones with shared personal lines or at coverage receivers but not at other
telephones with Shared SA buttons.
Telephone Differences
Direct-Line Consoles
The green LED next to an Auto Dial or DSS button on a DLC turns on when a
user turns on Do Not Disturb, indicating that the user is not available.
Queued Call Consoles
Do Not Disturb cannot be used on a QCC; Position Busy must be used instead.
The green LED next to a DSS button turns on when a user turns on Do Not
Disturb, indicating to the QCC operator that the user is not available.
Other Multiline Telephones
Turn on Do Not Disturb on a multiline telephone by pressing the programmed
Do Not Disturb button. The green LED next to the button goes on to indicate that
the feature is active. To turn off the feature, press the programmed Do Not
Disturb button again. The green LED next to the button turns off to indicate that
the feature is turned off. Feature codes cannot be used to turn Do Not Disturb
on and off.
In Release 2.0 and later, turning on Do Not Disturb on an analog multiline or
MLX-10 nondisplay telephone does not automatically post the Do Not Disturb
message; program a Posted Messages button for the message to be posted
automatically. In this case, when Do Not Disturb is turned on, the green LED
next to the Posted Messages button lights automatically and the system posts
turns off the green LED next to the Posted Messages button.
Single-Line Telephones
Do Not Disturb is not available on single-line telephones.
234
Do Not Disturb
. When Do Not Disturb is turned off, the system automatically