гарантия по первому требованию(Major differences distinguish letters of credit from "demand guarantees"; in the latter instrument the obligation to pay is conditioned within the terms of the bank's promise, therefore if the demand guarantee is payable upon the beneficiary's written first demand he is assured payment notwithstanding any defence related to any other underlying transactions. Proof of default is not needed and issuers are not concerned with the underlying contract nor can they raise any defence available to the underlying contracting party. wiki Alex_Odeychuk)
по первому требованию("(It is) a guarantee that imposes a primary obligation on the issuer to pay the beneficiary on its first demand (or on demand) where the primary obligor fails to perform the contract." practicallaw.comAlexander Matytsin)