<h1>Standard Input-Output Norms require imported polymer inputs to match the composition of exported polystyrene articles for compliance.</h1> Standard Input-Output Norms govern articles made of polystyrene under H31, specifying the required quantity of GPPS/HIPS granules per unit of exported product. The schedules require determination of permissible input proportions for manufacture and impose an obligation on applicants to ensure imported inputs are those used or required in the exported polystyrene articles, creating an import use verification requirement under the Foreign Trade Policy.