收到一个信用证后,怎样才能识别该证是不是背对背信用证

有BACK-TO-BACK LETTER OF CREDIT的字样。
有限制条款：The credit amount is payable to you upon our receipt from the above accountee of the documents required under the Bang(Issuing Bank of Original Credit ) L/C No.xxxxx Dated xxxx.
在收到原证规定的单据才兑付背对背信用证项下的汇票。

信用证（Letter of Credit，L/C）是开证银行根据申请人的申请向受益人开出的、由开证银行凭规定单据履行到期付款义务的保证性文件。