Program "Do not disturb" on business phone

It's pretty straightforward. You pick a spare button, dial FEAT 00 press the blank button (with a light) and press FEAT 01. There are considerations that I'll reproduce here.

Do Not Disturb (F01) 8
Use this feature to be able to press a programmed button to prevent incoming calls for the
extension from ringing (lights still flash). When Do Not Disturb is on, outside callers hear ringing
while inside callers hear a busy signal. You should use Do Not Disturb only if someone answers
outside calls for your extension when you do not answer them.
Considerations 8
■ Do Not Disturb is available only on system telephones.
■ Do Not Disturb requires a button with lights. When the Do Not Disturb feature is on, the light
is also on, indicating that the telephone will not ring.
■ Use Do Not Disturb when you do not want the auto attendant or the voice messaging system
to transfer calls to you.
■ Use Do Not Disturb if you are assigned to a Hunt Group and you leave your desk, so calls to
the Hunt Group will skip your extension and ring immediately at the next available extension
in the group.
■ To avoid missing calls when Do Not Disturb is not needed, turn it off.
■ If Do Not Disturb is active at a doorphone alert extension, the person at the doorphone hears
signaling, but the alert extension is not signaled.
■ Unanswered calls that are transferred from an extension with Do Not Disturb active ring at
that extension if they transfer return.
■ Extensions with Do Not Disturb activated do not receive Caller ID information, unless the call
is answered.
■ Users with Automatic VMS Cover Assigned or with VMS Cover turned on can activate Do
Not Disturb to Send All Calls immediately to their voice mailbox.
■ Users with Call Coverage turned on can activate Do Not Disturb to Send All Calls
immediately to the covering extension.
■ You cannot use Call Screening (F25) when Do Not Disturb is turned on.

Carl