Great care should be taken with the security of the instrument, as it is legally almost as good as cash. Exceptions Under the Code, the following are not negotiable instruments, although the law governing obligations with respect to such items may be similar to or derived from the law applicable to negotiable instruments: Bills of lading and other documents of title, which are governed by Article 7 of the Code. However, under admiralty law, a bill of lading may either be a negotiable or 'order' bill of lading or a nonnegotiable or 'straight' bill of lading. Deeds and other documents conveying interests in real estate, although a mortgage may secure a promissory note which is governed by Article 3 IOUs Letters of credit, which are governed by Article 5 of the Code Modern relevance Although often considered foundational in business law, the modern relevance of negotiability has been questioned. Negotiability can be traced back to the 1700s and Lord Mansfield, when money and liquidity was relatively scarce. The holder in due course rule has been limited by various statutes. Concerns have also been raised that the holder in due course rule does not align the incentives of the mortgage originators and the assignees efficiently. See also Bearer instrument Hundi Negotiable cow References External links Bill of Exchange FAQ on TheBenche.com Securities (finance) Legal documents Payment systems Negotiable instrument law Business law Accounting source documents Money market instruments