What are the requirements of negotiability under the Code? List and briefly summarize them.

(1) Be in writing. The instrument must be written, which includes printing, typewriting, handwriting, or other intentional tangible expression and need not be on paper.
(2) Be signed by the maker or drawer. "Signed" can be a signature, "x," thumbprint, rubber stamp, or "any symbol executed or adopted by a party with present intention to authenticate a writing." Location of the signature on the document is unimportant.(3) Be an unconditional promise or order to pay. The payment cannot be based on the occurrence or nonoccurrence of some other event. It must be more than a mere acknowledgment of an existing debt or an authorization or request for payment. (4) State a specific sum of money. Payment must be for an amount that is "ascertainable from the instrument itself without reference to an outside source." It must be payable in a medium of exchange authorized or adopted by a sovereign government as part of its currency. (5) Be payable on demand or at a definite time. On demand is at sight or on presentment. At a definite time can be
(a) on a stated date or a fixed period after that date,
(b) at a fixed period after sight or acceptance,
(c) at a definite time subject to any acceleration,
(d) at a definite time subject to extension at the option of the holder, or to extension to a further definite time at the option of the maker or acceptor or upon or after a specified act or event. (6) Payable to order or to the bearer. To order is to a specific person, to bearer is the person in possession of the instrument. (7) It must contain no other undertaking or instruction.