This specification applies to rubber and rubber-like insulation of cables and flexible cords intended for use in electrical installations at working voltages not exceeding 11,000 volts. It gives a classification of insulation compounds in terms of characteristic constituent and maximum operating temperature, and prescribes the relevant physical properties and test requirements for each type. The tests prescribed in This Standard apply to insulation incorporated in a finished cable, cord or core, or to samples removed from the finished core, as may be specified in the particular test.