Samsung SGH-C225NBATMB User Manual
Page 152
 
Glossary 
152
PUK (PIN Unblocking Key)
Security code used to unlock the phone when an incorrect PIN 
has been entered three times in succession. The eight-digit 
number is supplied by the service provider with the SIM card.
Roaming
Use of your phone when you are outside your home area (when 
travelling for example).
SDN (Service Dialing Numbers)
Telephone numbers supplied by your network provider and 
giving access to special services, such as voice mail, directory 
inquiries, customer support and emergency services.
SIM (Subscriber Identification Module)
Card containing a chip with all the information required to 
operate the phone (network and memory information, as well 
as the subscriber’s personal data). The SIM card fits into a small 
slot on the back of the phone and is protected by the battery.
SMS (Short Message Service)
Network service sending and receiving messages to and from 
another subscriber without having to speak to the 
correspondent. The message created or received can be 
displayed, received, edited or sent.
Soft Keys
Two keys marked 
and
on the phone, the purpose of
which: