This part of IEC 60512 covers additional, supplemental test method specifications to extend the upper frequency for the test connectors and associated indirect-reference test fixtures used in the signal integrity and transmission performance tests specified in IEC 60512-27-100. In support of de-embedded crosstalk and related transmission requirements specified in IEC 60603-7-81, for frequencies up to 2000 MHz, these supplemental specifications extend the upper test frequency from IEC 60512-27-100 up to 500 MHz to the upper test frequency of IEC 60512-28-100 up to 2000 MHz. This standard covers measurements of connector signal integrity and transmission performance of 8-pole connector types defined in these published connector series standards: IEC 60603-7-2 IEC 60603-7-3 IEC 60603-7-4 IEC 60603-7-5 IEC 60603-7-41 IEC 60603-7-51 IEC 60603-7-81 This standard covers respective performance test procedures of connector signal integrity and transmission performance defined in these published connector test method series standards: IEC 60512-26-100. IEC 60512-27-100 IEC 60512-28-100 These additional specifications are also suitable for testing the series related lower frequency backward compatible connectors. However, the actual measurement or test procedure specified in the detail specification for any particular connector remains the reference conformance test for that connector category; see Table 1. The test procedures of IEC 60512-27-100 affected by these supplemental specifications are: insertion loss, test 27a; return loss, test 27b; near-end crosstalk (NEXT) test 27c; far-end crosstalk (FEXT), test 27d; transverse conversion loss (TCL), test 27f; transverse conversion transfer loss (TCTL), test 27g. transfer impedance (ZT ), see IEC 60512-26-100, test 26e. coupling attenuation (aC), see IEC 62153-4-12.