Tariff classification of rice parboiling machinery: treated as composite rice mill equipment and classified under grain processing heading. Where parboiling machinery and drier units form part of an integrated rice processing plant, the composite is to be classified according to the principal function of the whole; because parboiling/dampening is a component of paddy processing and certain dampening functions fall outside the steaming/drying description, such machinery used in conjunction with a rice mill is to be classified with rice processing machinery under the grain processing heading.