Siemens HiPath 4000 - Manual (Page 94)

Step by Step
Telephone blocking
86
either:
6 7 Enter the service code.
or:
> < [
Select the menu item and confirm.
> < [
Select the menu item and confirm.
then:
o
Enter the PIN (code no.).
[
Press. If the PIN is correct, it will be confirmed with:
"carried out" on the display.
PIN / COS?
CHANGE COS