Recycling by product massive number of types of plastic, they each carry a resin identification code, and must be sorted before they can be recycled. This can be costly; while metals can be sorted using electromagnets, no such 'easy sorting' capability exists for plastics. In addition to this, while labels do not need to be removed from bottles for recycling, lids are often made from a different kind of non-recyclable plastic. To help in identifying the materials in various plastic items, resin identification code numbers 1-6 have been assigned to six common kinds of recyclable plastic resins, with the number 7 indicating any
Personal identification number Personal identification number A Personal Identification Number, pronounced "pin"; (often spoken out loud "PIN number", introducing redundancy) is a numeric or alpha-numeric password used in the process of authenticating a user accessing a system. The personal identification number has been the key to flourishing the exchange of private data between different data-processing centers in computer networks for financial institutions, governments, and enterprises. PINs may be used to authenticate banking systems with cardholders, governments with citizens, enterprises with employees, and computers with users, among other uses. In common usage, PINs are used in ATM or POS transactions, secure access control (e.g.