This part of IEC 1248 specifies how to prepare detail specifications for signal transformers to be released under the terms of IEC 1248-1 (QC 260000) capability approval. It includes a blank detail specification (BDS), which shows the format, and indicates which tests are considered to be appropriate to this type of component, although the final selection of tests to be included in the inspection schedule is at the discretion of the specification writer. It also lists appropriate ratings and characteristics. The components covered by this part of IEC 1248 are essentially concerned with uni-directional and bi-directional transfer of signals (information) from one section of a circuit to another. These signals may have some power content, and may cover a band of frequencies.