IEC 60747-5-6:2016 specifies the terminology, the essential ratings and characteristics, the measuring methods and the quality evaluations of light emitting diodes (LEDs) for general industrial applications such as signals, controllers, sensors, etc. LEDs for lighting applications are out of the scope of this part of IEC 60747. The types of LED are divided into the following five classes: a) LED package; b) LED flat illuminator; c) LED numeric display and alpha-numeric display; d) LED dot-matrix display; e) I LED (infrared-emitting diode). LEDs with a heat spreader or having a terminal geometry that performs the function of a heat spreader are within the scope of this part of IEC 60747. An integration of LEDs and controlgears, integrated LED modules, semi-integrated LED modules, integrated LED lamps or semi-integrated LED lamps, are out of the scope of this part of IEC 60747. This first edition of IEC 60747-5-6, together with IEC 60747-5-4, IEC 60747-5-5 and IEC 60747-5-7, cancels and replaces IEC 60747-5-1, IEC 60747-5-2 and IEC 60747-5-3, published in 1997, and their amendments. This edition constitutes a technical revision. This edition includes significant technical changes to the clauses for light emitting diodes in IEC 60747-5-1:1997, IEC 60747-5-2:1997 and IEC 60747-5-3:1997, including their amendments.