Many of the functions on a Norstar set are invoked by what are referred to as a "Feature code". This is done by pressing the "Feature" button followed by some key sequence.
Any mode that can be enabled such as "do not disturb" or "call forward" can be disabled by dialing the same feature code by inserting a "#" between the "Feature" button and the key sequence.
For example, to turn on "Do Not Disturb" is Feature 85, to turn it off would be Feature # 85.
Here is a list of common codes (not necessarily all).
The "Feature" button will be represented by an "F" to save typing.
F *0 button inquiry
F *1 assign external number autodial to a button
F *2 assign internal autodial to a button
F *3 assign feature to a button
F *4 program personal speed dial (local to that phone only)
F *6 change ring tone
F *7 display contrast
F *80 adjust ring volume
F *81 move line appearance to new position
F 0 speed dial (followed by a 2-digit number)
F 1 send message
F 2 ring again
F 3 conference
F 4 call forward
F 5 last number redial
F 60 Page-General
F 61 Page on sets speakers only (add page zone number optional i.e. 610 or 611)
F 62 Page on overhead speakers only (add page zone optional)
F 63 page both set and speakers
F 66 voice call
F 67 save number
F 69 priority call
F 70 transfer
F 74 call park
F 75 group pickup
F 76 directed pickup
F 77 see call duration
F 81 Move line appearance
F 82 camp on
F 83 privacy on lines
F 84 line redirect
F 85 do not disturb
F 86 music on (uses the Music from the "music on hold" source)
F 88 Voice Call Deny
F 802 group listen
F 803 display time while on a call