[经] irrevocable and confirmed credit

bù kě chè xiāo bǎo duì xìn yòng zhuàng ㄅㄨˋ ㄎㄜˇ ㄔㄜˋ ㄒㄧㄠ ㄅㄠˇ ㄉㄨㄟˋ ㄒㄧㄣˋ ㄩㄥˋ ㄓㄨㄤˋ