The CISG contains articles for the risk of loss and passing it through 66-70. The buyer does not be discharged from his obligation to pay the price after the risk has passed to him according to the CISG. The risk passes to the buyer when the goods are handed over to the carrier in principle. The risk in respect goods sold in transit passes to the buyer from the time of the conclusion of the contract. But the CISG has no definition of the types of risks covered by the rules on transfer of risk, thus leaving uncertainty. The types of risks covered by the CISG might include the physical loss or damage, deterioration, or perishing of the goods, the risk of loss of documents relating to the goods, and legal risk. Also, the CISG does not attempt to define trade terms (CIF, C&F, FOB carrier at named point of shipment, FAS, FOB carrier at named point of destination, ex ship, and the like). These terms, which (among other things) allocate the risk of loss or damage during transit, are too detailed and complex in their operation to be easily susceptible to international codification. Moreover, their definition is subject to change in the light of changing commercial custom and should not be frozen by the international legislation. Less easy to understand, however, is the CISG`s failure to address problems of risk of loss or damage that arise in documentary sales transactions in which trade for the international sale of such documentary transactions probably constitute the great majority of contracts for the international sale of goods, yet the CISG deals with documentary transactions only incidentally.