DCs can be irrevocable or revocable. With a revocable DC, the buyer can change or cancel it after issuance. You should always insist on an irrevocable DC so that it can’t be cancelled without your consent.
Import & export
How Documentary Credits Work
In basic terms, a Documentary Credit (DC) is an undertaking by a bank to make payment, provided the terms of the DC are met. There are several types of DC – the main difference is that some are more suited to transactions involving middlemen or traders.