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Glossary
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PIN (Personal identification number)
Security code that protects the phone against
unauthorised use. The PIN is supplied by the
service provider with the SIM card. It may be a four
to eight-digit number and can be changed, as
required.
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
network service area (when travelling for example).
SDN (Service dialling 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 in
the back of the phone and is protected by the
battery.