Magna Steel Erectors, a Canadian manufacturer and exporter of steel components in bridge building has negotiated a deal with BridgeCon Inc., an American bridge construction firm. They have been doing business for several years and have used both Open Account and Letters of Credit. Recently BridgeCon has experienced some challenges in paying on time and maintaining its creditworthiness. Rumours are rampant about the potential for BridgeCon to encounter severe financial difficulty. As a result, Magna is worried about being paid for future shipments. In addition, Magna has recently lost several key engineers and project managers which has severely impacted their ability to perform key work and complete some recent projects on time and to the satisfaction of previous customers. Name and describe two types of Standby Letters of Credit that could address the concerns that Magna has about BridgeCon or that BridgeCon might have about Magna