If in short, the PIN2 code is an additional custom lock use SIM Card and Moble Phone.
Used on some phones, for various locks:
— blocking outgoing calls to your phonebook and special numbers (112 or other) (used on the Nokia)
— children mode, when any call from the device occurs on a pre-opened menu in the room (not compatible with previous paragraph)
— lock some of the settings of the phone
Protection to short numbers should be on the part of the operator:
— in megaphone so
— the rest do not know