A common format for data files and exchange medium used for the interchange of various types of fault, test, or simulation data for electrical power systems is defined in this standard document. Sources of transient data are described, and the case of diskettes as an exchange medium is recommended. Issues of sampling rates, filters, and sample rate conversions for transient data being exchanged are discussed. Files for data exchange are specified, as is the organization of the data. A sample file is given.