AT&T 7406BIS - Manual (Page 14)

Last Number Dialed Automatically redials the last number you dialed, either an
extension or an outside number. Use to save time in redialing a busy or unanswered
number. Available with DEFINITY Generic 2 and System 85 R2V4 and some R2V3
systems. Check with your System Manager to see if the feature is available in your
system.
Leave Word Calling (LWC) Leaves a message for another extension to call you back.
The called party will be able to dial message center, AUDIX, or a covering user to
retrieve a short, standard message that gives your name and extension, the date and
time you called, and the number of times you called. Use any time you want to have
someone call you back; it will help cut down on repeated call attempts.
Message Retrieval Lets you know that a caller has left a message for you when the
message light goes on. You can then follow your System Manager’s local message
retrieval procedures to get your message. See the Message Retrieval procedures
under the Display Features heading.
Mute Allows you to turn off the microphone of the speakerphone or the handset so
that the caller cannot hear you.
Priority Calling Allows you to call another extension with a distinctive 3-burst ring
to indicate that your call requires immediate attention. Use when you have important
or timely information for someone.
Select Ring Allows you to select your own personalized ring from among 8
available ringing patterns. Use to distinguish your ring from that of other nearby
voice terminals.