IEC 60598-2-20:2014 specifies requirements for lighting chains fitted with series, parallel or a combination of series/parallel connected light sources for use either indoors or outdoors on supply voltages not exceeding 250 V. For combinations where rope lights (also known as sealed lighting chains) are included, see IEC 60598-2-21. This fourth edition cancels and replaces the third edition (2010). This edition includes the following significant technical changes with respect to the previous edition, where the requirements for rope lights (sealed lighting chains) have been removed and are now dealt with in IEC 60598-2-21.