This specification applies to rubber and rubber-like sheathing of cables and flexible cords intended for use in electrical installations at working voltages not exceeding 11 kV. It gives a type classification of sheathing compounds in terms of intended application, characteristic constituent and maximum operating temperature, and prescribes relevant physical properties and test requirements for each type. The tests prescrived apply to sheathing incorporated in the finished cable or cord or to samples removed from the cable or cord, as may be specified in the particular test.