Rationalization to the stage of allocation of product to particular manufacturers is rejected as impracticable in the existing organization of industry.Reduction of variety on the basis of British Standard Specifications is discussed with illustrations therefrom and with respect to certain apparatus for which no standards have been instituted.Dimensional identity is suggested for components which for practical convenience should be interchangeable.The scope for a large reduction in variety of sizes and types of cable, both flexible and armoured, is pointed out.The advantage of restriction in the number of sizes of cover glasses for flameproof lighting fittings is suggested, and the lack of agreed standards of speed in relation to output for certain types of motors is commented upon.The lack of any agreed standards of voltage is commented upon.