ES 39110 is a Hyundai Engineering Standard, and the designation identifies both the system and the class of the document: the letters indicate an engineering standard rather than a drawing or a process specification, and the five-digit number places the requirement in a subject range, so that documents with neighbouring numbers address related parts of the electrical and electronic installation. The trailing pair of digits identifies the revision or the part of the document, which in practice means that a supplier should quote the full designation rather than the number alone. Requirements of this class state the disturbances to be applied to a component at its mounting position and the levels that correspond to it, and the applicable one is named in the supplier's engineering specification along with the manufacturer's method documents.