Relates to flexible or semi-flexible radio-frequency cables of coaxial or twin conductor types designed for use in radio-communication equipment and in electronic devices employing similar techniques. The dielectric may be of solid. air-spaced, or semi-air-spaced types, consisting of a thermoplastic of low-loss polymeric resin, a thermosetting compound, or a mineral material. Establishes uniform requirements for judging the electrical, climatic and mechanical properties of radio-frequency cables and describes test methods.