Delegation of powers to collectors sets criteria for declaring warehousing stations and restrains extensions of warehousing periods. The delegation authorises Principal Collectors to declare warehousing stations and grant warehousing-period extensions subject to criteria: declaration depends on local industrial development, warehousing need, availability of public bonded warehouse facilities (with relaxation for certain export units), and adequate Customs staffing and training; cases outside criteria go to the Board. Extensions require assurance goods will not deteriorate, testing if necessary, valid grounds (lack of funds alone insufficient), shortest practicable duration with limits, liberal treatment for specified categories after condition checks, and monthly reporting to the Board for interest-waiver consideration.