New York Consolidated Laws, Uniform Commercial Code - UCC § 3-202. Negotiation

(1) Negotiation is the transfer of an instrument in such form that the transferee becomes a holder.  If the instrument is payable to order it is negotiated by delivery with any necessary indorsement;  if payable to bearer it is negotiated by delivery.

(2) An indorsement must be written by or on behalf of the holder and on the instrument or on a paper so firmly affixed thereto as to become a part thereof.

(3) An indorsement is effective for negotiation only when it conveys the entire instrument or any unpaid residue.  If it purports to be of less it operates only as a partial assignment.

(4) Words of assignment, condition, waiver, guaranty, limitation or disclaimer of liability and the like accompanying an indorsement do not affect its character as an indorsement.