instruments, documents which themselves represent the goods. Upon presentation of the documents, the goods will traditionally be in the control of the issuing bank, which provides them security against the risk that the buyer (who had instructed the bank to pay the seller) will repay the bank for making such a payment. In the event that the buyer is unable to make payment on the purchase, the seller may make a demand for payment on the bank. The bank will examine the beneficiary's demand and if it complies with the terms of the letter of credit, will honor the demand. Most letters of credit are governed by rules promulgated by the International Chamber of Commerce known as Uniform Customs and Practice for Documentary Credits. The current version, UCP 600, became effective July 1, 2007. Banks will typically require collateral from the purchaser for issuing a letter of credit and will charge a fee which is often a percentage of the amount covered by the letter of credit. Types Several categories of LCs exist which seek to operate in different markets and solve different issues. An example of these include: Import/export (Commercial): The same credit can be termed an import or export letter of credit depending on whose perspective is considered. For the importer it is termed an Import LC and for the exporter of goods, an Export LC. Revocable/Irrevocable: Whether a LC is revocable or irrevocable determines whether the buyer and the issuing bank are able to manipulate the LC or make corrections without informing or getting permissions from the seller. According to UCP 600, all LCs are irrevocable, hence in practice the revocable type of LC is increasingly obsolete. Any changes (amendment) or cancellation of the LC (except when expired) is done by the applicant (buyer) through the issuing bank. It must be authenticated and approved by the beneficiary (seller). Confirmed/Unconfirmed: An LC is said to be confirmed when a second bank adds its confirmation (or guarantee) to honor a complying presentation at the request or authorization of the issuing bank. Restricted/Unrestricted: Either the one advising bank can purchase a bill of exchange from the seller in the case of a restricted LC, or the confirmation bank is not specified, which means that the exporter can show the bill of exchange to any bank and receive a payment on an unrestricted LC. Deferred/Usance: A credit that is not paid/assigned