ISO/TS 7637-4 is the technical specification version of the document that defines transient conduction along shielded high-voltage supply lines in road vehicles. A technical specification is published when the subject matter is still developing and the committee wishes to make guidance available before a full international standard can be agreed, and that situation applied to the high-voltage transient environment of electric vehicles, where field experience was limited and practice among manufacturers was still forming. The document therefore presents the test waveforms and the method for applying them to the shielded high-voltage circuit with the understanding that the requirements may be revised. In practice it was the basis on which traction system components were qualified before the corresponding part of the series reached full international standard status, and the two documents should be read together where a project refers to either. The test configuration and the generator characteristics are essentially those of the published part.