The fraud exceptionprinciple is an important practice gradually established in the practice of international trade to deter frauds in the use of letters of credit.
信用证欺诈例外原则，是各国在国际贸易实践中逐渐建立完善的一种遏制信用证欺诈的重要制度。
2
There is one exception to this general principle.
这个一般性原则有一例外。
《牛津词典》
3
So this is the first exception that you need to the Aufbau principle.