Nokia N Serie Manual Del Usuario página 117

UPIN code—This code may be supplied with the USIM card.
The USIM card is an enhanced version of the SIM card and
is supported by UMTS mobile phones.
PIN2 code—This code (4 to 8 digits) is supplied with some SIM
cards, and is required to access some functions in your device.
Lock code (also known as security code)—This code (5 digits)
can be used to lock the device to avoid unauthorized use.
The factory setting for the lock code is 12345. To avoid
unauthorized use of your device, change the lock code. Keep
the new code secret and in a safe place separate from your
device. If you forget the code, contact your service provider.
Personal unblocking key (PUK) code and PUK2 code—These
codes (8 digits) are required to change a blocked PIN code
or PIN2 code, respectively. If the codes are not supplied
with the SIM card, contact the operator whose SIM card is
in your device.
UPUK code—This code (8 digits) is required to change a
blocked UPIN code. If the code is not supplied with the USIM
card, contact the operator whose USIM card is in your device.
Digital certificates should be used if you want to connect to
an online bank or another site or remote server for actions
that involve transferring confidential information. They
should also be used if you want to reduce the risk of viruses
or other malicious software and be sure of the authenticity
of software when downloading and installing software.
Important: Even if the use of certificates makes the
risks involved in remote connections and software
installation considerably smaller, they must be used
correctly in order to benefit from increased security.
The existence of a certificate does not offer any
protection by itself; the certificate manager must
contain correct, authentic, or trusted certificates
for increased security to be available. Certificates
have a restricted lifetime. If "Expired certificate" or
"Certificate not valid yet" is shown even if the
certificate should be valid, check that the current
date and time in your device are correct.
Before changing any certificate settings, you must
make sure that you really trust the owner of the