Summary: Goods may be retained if undervalued and written notice of detention is given. Valuation must be declared accurately in the bill-of-entry, ascertain the real value and documents may be requested for verification. The declared value should be tested strictly, and the Collector of Customs is not obliged to take over the entire consignment if goods are detained. Allowance for ullage provided for wine, spirits, and beer, and excess allowance may be permitted in specific scenarios. The Governor-General in Council has the authority to establish the tariff value while the real value is distinctly defined, and alterations to the entry of under-valued items are allowed in certain circumstances.