Samsung SGH-X105NBATMB - Manual (Page 88)

Phone Settings
85
FDN Mode
The FDN (Fixed Dial Number) mode, if supported by your SIM
card, allows you to restrict your outgoing calls to a limited set of
phone numbers.
The following options are available.
Disable: you can phone any number.
Enable: you can only call phone numbers stored in the
phonebook. You must enter your PIN2.
Note: Not all SIM cards have a PIN2. If your SIM card does not, this
menu option is not displayed.
To change your PIN2, refer to the Change PIN2 menu option
(Menu 5.5.6) below.
Change PIN2
The Change PIN2 feature allows you to change your current
PIN2 to a new one. You must enter the current PIN2 before you
can specify a new one.
Once you have entered a new PIN2, you are asked to confirm it
by entering it again.
Note: Not all SIM cards have a PIN2. If your SIM card does not, this
menu option is not displayed.