DIN EN 62305-4 (VDE 0185-305-4) deals with the protection of structures with electrical and electronic systems against effects of lightning electromagnetic impulse (LEMP) by surge protective measures (SPM). They contain an individual combination of the following protective measures: earthing and bonding, shielding of internal lines, line routing and shielding, coordinated SPD system (SPD = Surge Protective Device). The characteristic values of the protective measures shall correspond to the selected lightning protection level (LPL). The base for the construction of the SPM is the lightning protection zones concept. The annexes of this standard provide the basis of electromagnetic environment evaluation in a lightning protection zone, additional information for SPM protection in existing structures, rules for the selection and installation of a coordinated SPD system, and characteristics which shall be taken into account when selecting SPDs. For planning, installation and testing of LEMP protection systems, a lightning protection expert is required in clause 9, with broad knowledge of EMC and knowledge of installation practices. The term lightning protection expert has not been specified in the text of the International Standard IEC 62305-4. For this reason, Committee K 251, which is responsible for the national standard, adopted an explanation for the term lightning protection expert which takes into account the field of planning, testing and installation. The responsible committee is K 251 "Blitzschutzanlagen und Blitzschutzbauteile" ("Lightning protection systems and lightning protection components") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.