LED manufacturers bin (or rank) LEDs based on brightness. LED brightness is checked during manufacturing and the parts are sorted into “bins” so that consistent brightness quality is provided. The tables on this slide show some LED datasheet binning groups. As an example, if a tested LED has a luminous intensity of 30 mcd it will be placed in an “N” bin. When customers use an LED, they may not always have the option of specifying the brightness bin or rank. This is a potential problem because the circuit may have been designed for a 30 mcd LED but the actual LED received could 5x brighter at 150 mcd.