"This part of IEC 60598 specifies requirements for lighting chains fitted with series- or parallelor a combination of series/parallel-connected incandescent lamps for use either indoors or outdoors on supply voltages not exceeding 250 V. NOTE 1 A Christmas tree chain is an example of a lighting chain fitted with series or series/parallel connected lamps. A chain for illuminating ski-tracks or promenades is an example of a lighting chain fitted with parallel connected lamps. NOTE 2 For lighting chains fitted with lampholders of the push-in type@ the appropriate requirements of this part of IEC 60598 apply. NOTE 3 In some countries@ the term ""strings"" is used instead of ""chains"". NOTE 4 For lighting chains with non-standardised lamps (e.g. lamps of the push-in type) the lamps are regarded as a part of the lighting chain and consequently included in the testing (and thereby in the certificate@ if any)."