Save your PIN codes
on pin cards
A personal identification number (a PIN code) is a numeric password of 4-digits given to you from your bank to get access to you account with debit and credit cards.
For you SIM card in you smartphone you have a pin code from you mobile company in order to get access to you smart phone.
So undoubtedly you have many PIN codes for your smart phones, bank and credit cards to remember, maybe also pin codes for you family.