Modvat credit on exported goods' inputs allowed for exempt small scale units, subject to separate accounts and adjustment or refund. SSI units opting for full exemption on home-consumption clearances may claim Modvat credit on inputs used exclusively in export production, provided they maintain separate accounts from raw material to final product segregating export and home-consumption production; such credit may be applied to duty on similar home-consumption clearances after exemption limits are exceeded or refunded where adjustment is not possible in accordance with the prescribed procedure.