This standard (Part IV) covers the requirements of enamelled rectangular and square copper wires with temperature index 155 (for example, copper conductors covered with enamel on a polyester base ).
IS 3855 Pt.4-1981 history
1981IS 3855 Pt.4-1981 Specification for rectangular and square enamelled copper conductors with a temperature index of 155 Part IV Wires