Panasonic KX-T336 System Reference Manual page 287

2.07 Private CO (PCO)
Description
It is possible to connect a CO line as if it were
connected directly to a DN button on a PITS.
This operation is called Private CO (PCO).
It is then no longer possible to place outgoing
calls from other extensions using this CO line.
Also, an incoming call from the CO line assigned
as PCO will arrive only at this PITS.
To program a Private CO line, set "Group-Trunk
Group", Type to PVL and program the CO line to
the Private trunk group in "Trunk-CO Line", Trunk
Group.
Also, program the DN button on the PITS to
PRV-CO using "Extension-Station (2/3)", Type
and assign the physical number of the Private
CO line under Number.
Programming
System Programming
"Group-Trunk Group (1/2)",
Type
"Trunk-CO Line", Trunk Group
"Extension-Station (2/3)",
Type and Number
Reference
VT Dumb
9-E-1.01 10-C-14.00
9-F-1.00 10-C-18.00
9-G-1.02 10-C-24.00
3-D-15
Conditions
A Private CO button lights up red at the times
below.
1) When the Private CO line is not In Service.
2) When the Private CO line has been set to
CO Busy-Out.
3) When access using the Trunk Verify
function is made by the Attendant Console.
A call held on a Private CO button can not be
retrieved by other extensions, however, an
incoming call to a Private CO button can be
transferred.
When an incoming CO call arrives, ringing occurs
instantly. Delayed ringing is not available.