AT&T SYSTEM 25 User Manual page 36

outside line
paging
park
PDC
preferred
route tone
program
redial
ringback tone
speaker
a line to the Central Office or other system.
Outside lines may be accessed by dialing an
access code.
feature that allows you to access paging
equipment from System 25 voice terminals.
feature like hold except that it allows you to
answer the parked call from any voice
terminal.
(Personal Dial Code) extension number that
is assigned to an individual and is normally
associated with the voice terminal at the
individual's desk. Floating PDCs are not
associated with a particular voice terminal
and can be used only when they are signed
in at a voice terminal.
five short tones indicating that the outside
call you just placed is waiting to go over the
most preferred route (as determined by the
System Administrator). You can either wait
by staying off-hook or hang up and try
again later.
ability to store a telephone number, account
code, feature access code, or PDC so you
can access it by pressing a single button or
by dialing a code.
feature that allows you to redial the last
inside or outside number you dialed (up to
15 digits).
repeating on/off tone indicating that the
number you dialed is ringing.
button that allows you to place calls and
converse with the other party without
lifting the handset.
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