Special economic zone customs regime: duty-free admission tied to authorised use, bonds, monitoring and recovery obligations. The Rules create a customs framework allowing duty-free admission and use of goods in designated SEZ processing areas for authorised operations, subject to secured demarcation, documentation, inspection and strict accounting. Duty becomes payable where goods are diverted, used outside authorised operations, not accounted for, or upon transfer to the domestic tariff area; developers and units must furnish bonds, submit quarterly returns, and face monitoring, recovery and interest liabilities if foreign exchange or utilization conditions are not met.