买卖双方在制定合同时，如果有理解一致的具体规则可供参照，他们就肯定能简单、可靠地确定各自的责任。

买卖双方在制定合同时，如果有理解一致的具体规则可供参照，他们就肯定能简单、可靠地确定各自的责任。

If, when drawing up their contract, buyer and seller have some commonly understood rules to specifically refer to , they can be sure of defining their respecctive responsibilities simply and safely .