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
National identification number '5' or '7'. During Portuguese rule, Macau had no unified identification system, and several departments had the authority to issue identity cards to Macau citizens and residents. Since 1992, the Identification Department (once known as SIM, now called DSI) has become the unitary authority to issue identity cards. It has adopted the above-mentioned numbering policy. Macau's Finance Department has also adopted identification number as a tax reporting number, for tax filing purposes. In Malaysia, a 12-digit number (format: YYMMDD-SS-###G, since 1991) known as the National Registration Identification Card Number (NRIC No.) is issued to citizens and permanent residents on a