(b) The statement of a rule in this article does not by itself require, imply, or negate application of the same or a different rule to a situation not provided for, or to a person not specified, in this article.
(c) With the exception of this subsection, subsections (a) and (d), sections 5-102(a)(9) and (10), 5-106(d), and 5-114(d), and except to the extent prohibited in sections 1-302 and 5-117(d), the effect of this article may be varied by agreement or by a provision stated or incorporated by reference in an undertaking. A term in an agreement or undertaking generally excusing liability or generally limiting remedies for failure to perform obligations is not sufficient to vary obligations prescribed by this article.
(d) Rights and obligations of an issuer to a beneficiary or a nominated person under a letter of credit are independent of the existence, performance, or nonperformance of a contract or arrangement out of which the letter of credit arises or which underlies it, including contracts or arrangements between the issuer and the applicant and between the applicant and the beneficiary.