n5 Although it appears to be uncommon, an issuer of a standby letter of credit may demand security from its customer in the form of cash collateral or personal property as a condition for issuing the letter of credit. In the event of a draw on the letter of credit, the issuer would then have recourse to the pledged security, up to the value of the draw, without requiring its customer to pay additional money. Whether a real estate lender's draw on a standby letter of credit backed by security, and not by a mere promise to pay, would fall within the mixed security rule is a difficult question that need not be addressed here.