Nortel Meridian SL-100 Reference Manual page 315

primary directory number (PDN)
The primary directory number is the directory number assigned to Key 1 of
a Meridian modular telephone. The primary directory number uniquely
identifies the telephone set from among the many directory numbers that can
be assigned to it. (The M2006 set is only a single-line set; therefore, Key 1
is the only directory number key.)
private branch exchange (PBX)
A PBX is a small local telephone office, either automatic or manually
operated, serving extensions in a business complex and providing access to
the public network.
product engineering code (PEC)
A PEC is an eight-character code that provides a unique identification for
each marketable product manufactured by Nortel.
Program key
The Program key (P key) controls access to the display or Meridian
programmable data adapter for parameter selection. The Program Mode is
activated by pressing P.
pseudorandom pattern
A transmission pattern with the properties of random data generated in such
a manner that another circuit can synchronize on the pattern and detect
individual transmission bit errors. Pattern 511 follows CCITT specification
O.152.
PUD
Call Pickup Denied
pulse code modulation (PCM)
Pulse code modulation is a form of modulation in which the modulating
signal is sampled and the sample quantized and coded, so that each element
of information consists of different kinds or numbers of pulses and spaces.
PVC
See polyvinylchloride.
RAG
See Ring Again.
Release key (Rls)
This fixed key is located above the Hold key and to the right. This key is
used to release a call from the telephone set.
Meridian SuperNode MSL-100 Meridian Modular Telephones Reference Manual MSL11
List of terms 18-17