AEG M 300 User Manual page 37

21.1 Abbreviations and explanations
GSM Global System of Mobile Communication.
SIM Subscriber Identity Module.
PIN Personal Identity Number. Usually refers to PIN1.
Supplied with SIM card; Used to unlock the SIM card.
PUK Personal Unlock Code. Supplied with SIM card. It is
used to unlock the SIM card if you input wrong PIN
code three times consecutively and the SIM card is
locked. You can also use it to modify PIN code.
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