Customs exemptions conditioned on certified end use and undertakings, with duty recovery where conditions are unmet. Notification grants conditional customs duty exemptions or concessional rates for specified imports across Chapters 1-99 where importers produce designated certificates, registrations or undertake specific use-restrictions. Compliance mechanisms include production of officer-issued certificates, registration with sectoral councils or agencies, execution of bonds/undertakings, and post-import verification. Failure to satisfy conditions or to produce required proof renders the importer liable to pay the difference between the duty otherwise leviable and that already paid, often with interest, and allows appropriation of securities.