Samsung 08/2004 - Manual (Page 173)

Access codes
172
PIN2
The PIN2, supplied with some SIM cards, is required
to access some functions, such as charging unit
counters. These functions are only available if
supported by your SIM card.
If you key in an incorrect PIN2 three times in
succession, key in the PUK2 and press the Ok soft
key to unlock the phone. Key in a new PIN2 and
press the Ok soft key. Key in the new PIN2 again
and press the Ok soft key.
PUK
The PUK (PIN Unblocking Key) is required to change
a blocked PIN. The PUK may be supplied with the
SIM card. If not, contact your local service provider.
If you key in an incorrect PUK ten times in
succession, the SIM card cannot be used anymore.
Contact your service provider for a new card.
You cannot change the PUK. If you lose the code,
contact your service provider.
PUK2
The PUK2, supplied with some SIM cards, is
required to change a blocked PIN2.
If you key in an incorrect PUK2 ten times in
succession, you cannot use the functions requiring
the PIN2. Contact your service provider for a new
card.