(1) When a paper whose contents at the time of signing show that it is
intended to become an instrument is signed while still incomplete in any
necessary  respect it cannot be enforced until completed, but when it is
completed  in  accordance  with  authority  given  it  is  effective  as
completed.
  (2)  If  the  completion  is  unauthorized  the  rules  as to material
alteration apply  (Section  3--407),  even  though  the  paper  was  not
delivered  by  the  maker or drawer; but the burden of establishing that
any completion is unauthorized is on the party so asserting.
Structure New York Laws
Part 1 - Short Title, Form and Interpretation
3-102 - Definitions and Index of Definitions.
3-103 - Limitations on Scope of Article.
3-104 - Form of Negotiable Instruments; "Draft"; "Check"; "Certificate of Deposit"; "Note".
3-105 - When Promise or Order Unconditional.
3-112 - Terms and Omissions Not Affecting Negotiability.
3-114 - Date, Antedating, Postdating.
3-115 - Incomplete Instruments.
3-116 - Instruments Payable to Two or More Persons.
3-117 - Instruments Payable With Words of Description.
3-118 - Ambiguous Terms and Rules of Construction.
3-119 - Other Writings Affecting Instrument.
3-120 - Instruments "Payable Through" Bank.