PIN code, PUK code, security code, lock code, unlock code, restriction code...
Clearly, there's alot of confusion out there as to what all these codes do, what they protect, how to get them and how to manage them. I'd like to clear that confusion up a litle bit with this article. The first thing you have to bear in mind is that your SIM card is actually the property of your network operator. SIM stands for "Subscriber Information Module". Stored in it is information that identifies you as the user of the phone in which the SIM is installed, and which ties that phone to your mobile phone number. Proof of this is if you swap SIMs with another phone and call your number it's the other phone that will ring, and if you place a call with your phone it's the other phone's owner who will be billed! The PIN, or "Personal Identification Number" is a 4-digit code (well, actually, some phones allow up to 8 digits but it is nearly always 4 digits), stored in encrypted form in the SIM and which protects your SIM from unauthorised use. Th...