Panasonic KX-TD500 System Reference Manual page 245

Programming
Retrieving a call held on GCO from SCO.
Assuming that Trunk Group 01 consists of the following CO lines and
GCO and SCO buttons are assigned as follows.
TG01
GCO-01 is in use at EXT.100 now.
GCO-01
EXT.100
GCO-01 is lit
in green.
CO line 10101 is captured by pressing GCO-01.
When a call on GCO-01 is put on hold at EXT.100, GCO-01 begins to
flash in green and SCO-10101 on EXT.101 begins to flash in red as
follows:
GCO-01
EXT.100
EXT.101 can retrieve a call held on GCO-01 by simply pressing the red
flashing SCO-10101.
System Programming
"Extension-Station (2/4,3/4)",
Type and Number
3-D-27
CO line 10101
CO line 10102
CO line 10103
CO line 10104
EXT.101
SCO-10101 is lit
in red.
EXT.101
Reference
VT Dumb
10-G-1.02 11-C-26.00
10-G-1.03
SCO-10101
SCO-10102
SCO-10103
SCO-10104
S
SCO-10101
SCO-10102
S
SCO-10103
S
SCO-10104
S