Panasonic KX-TD500 System Reference Manual page 711

<Type 1>
This function field is available for advancing to the next screen or returning to the
previous screen when there are multiple extension management screens, and
changing the display from extension number to extension name.
Type 1
F1
(LOOP & TRG)
F2
(Next Page)
F3
(Previous Page)
F7
(No./Name Change)
F8
(Function Select)
6-C-23
LOOP & TRG
screen
Move to the next Extension Management screen.
No change if only one screen.
Returning to the previous Extension Management
screen.
No change if only one screen.
Changing to
Extension Number
(Example)
FWD/DND
No.
X
1001
1002
Type 2
Changing to
F7
Extension Name
(Example)
FWD/DND
Name
Betty
Frank
X