Weel if you want to carry those assorted numbers in your wallet or a kit but are fearful someone will steal it and use them. It is simple. Add a joker.

A joker is any number you decide to add, subtract, multiply or divide.

Anything that will change the base or real number. Then if you need to use the actual number reverse the process. Pin numbers can be included in a phony phone number with or without a joker.

Or you could select one number in a credit card number. 1st, 4th whatever. Raise or lower it by 1. As long as you are consistant, remember what you did and don't write down the key. Your numbers are safe and still usable.