AT&T Definity ISDN 7507 - Manual (Page 11)

Conference Allows you to add a third party to a call, so that you can conduct a
3-way conversation. (If you wish to conference more than 3 parties, call your attendant
for assistance.) Use to set up time-saving conferences, or to spontaneously include a
third party important to a discussion. Note: If you have both an active call and a call
on hold, you must terminate one of them before you can use Conference.
Drop Disconnects from a call without requiring you to hang up the handset or press
the switchhook. Can also be used with the Conference feature to disconnect the last
party added. Use whenever you are using the handset and want to continue using it for
another action after ending a call.
Hold Puts a call in a holding state until you can return to it. While a call is on hold,
you can place another call, activate another feature, answer a waiting call, or leave your
voice terminal to do another task. Use when you have a call that you don’t wish to
drop, but which you have to interrupt briefly to do something else.
Intercom Gives you quick access to specified extensions. With Automatic Intercom,
you can call a predetermined partner by pressing a single feature button. With Dial
Intercom, you can call any member of a predetermined group of users by pressing a
feature button and then dialing the group member’s 2- or 3-digit code. Use to rapidly
dial frequently called numbers.
Last Number Dialed (Redial) 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.