Northern Telecom 3X8 Owner's Handbook Manual page 132

Displays
Note
If you use Do Not Disturb while an external call is ringing, the call
will be forwarded to the Prime telephone. It may also be
answered by anyone whose telephone shares the line it is on.
Once you turn Do Not Disturb on, calls will be forwarded to the
Prime telephone only if there is no other telephone on which the
line appears. (The Delayed Ring Transfer feature transfers all
unanswered calls to the Prime telephone after a specified time.)
PO84262701
Do Not Disturb
Your telephone is in Do Not Disturb
mode. To cancel Do Not Disturb,
q
press
Your telephone is receiving calls
n o r m a l l y .
DR5.1 Owner's Handbook
127