Input-output norms require specified input proportions for sodium citrate exports and mandate matching imported inputs to declared use. The SION prescribes an Input-Output Norm for sodium citrate requiring citric acid monohydrate as the input at a proportion of 0.740 units per unit of sodium citrate; applicants must ensure that goods sought for import and actually imported are those used or required in the export product and must verify the proportion of inputs used in manufacture.