The original post from this discussion is very similar to one of the ICC Official Unpublished Opinions available on this site .
The conclusion to that Opinion is as follows:
Conclusion/Analysis
UCP 500 offers no specific guidance with regard to the handling of letters of credit where the advising bank is requested to send the credit to the beneficiary via the intermediary of another bank (usually the bankers of the beneficiary). This "other" bank, usually referred to as a second advising bank, is not specifically acknowledged in the UCP.
This situation occurs where the beneficiary has provided the applicant with a specific request for the routing of a letter of credit. The issuing bank may not be in a correspondent relationship with that particular bank and therefore sends the credit to its correspondent with instructions to send it to the beneficiary via their bank. This will invariably mean that both banks will charge a fee for handling the advice of the credit.
Advising banks should route the advices of the credit as instructed by the issuing bank.
An advice produced by an advising bank which is attached to the text of the letter of credit constitutes a statement of that advising bank's actions which have been taken and/or will be taken upon the presentation of documents. The content of an advising bank's letter cannot change the terms of the underlying credit, but an advising bank is allowed to state its terms of handling. Stating that the credit is available with it by payment does not change the terms of the underlying credit, which remain as stated in the issuing bank's advice. The credit would still be available by negotiation with any bank.
It is for the beneficiary to read the letter of credit and any covering advice in order to understand the implications and/or services being offered by any bank involved in that particular transaction.
You can view the full text of this opinion if you insert "advising bank" in the all site search (searching only opinions). This Opinion is ranked 4.