"Unique code" refers to a specific combination of letters, numbers, or symbols that is different from any other code. It is used to identify or distinguish something, like a product, user, or transaction, from others. Full definition
The locks also offer a capacity of several unique codes that the user can customize for particular days and times. (nashvillechatterclass.com)
Digital wallets use unique coding for the person's phone and transaction, which makes it easier to trace if there's a problem. (rismedia.com)
The three discs fit into a standard - sized Blu - ray keepcase, which is topped by a lenticular slipcover and holds two inserts with unique codes. (dvdizzy.com)