<h1>Input-output norms for optical brightener require specified input proportions and verification that imports are used in export production.</h1> Standard input output norms prescribe constituent raw materials and specific proportional quantities per kilogram for Optical Brightener Agent C.I. Fluorescent Brightener 252 (Assay 33%), with the entry noted as suspended; applicants must ensure imported goods correspond to those actually used or required in the export product, establishing an import use verification obligation.