1. (a) "Incomplete instrument" means a signed writing, whether or not issued by the signer, the contents of which show at the time of signing that it is incomplete but that the signer intended it to be completed by the addition of words or numbers.
2. (b) Subject to subsection (c) of this section, if an incomplete instrument is an instrument under Section 12A-3-104 of this title, it may be enforced according to its terms if it is not completed, or according to its terms as augmented by completion. If an incomplete instrument is not an instrument under Section 12A-3-104 of this title, but, after completion, the requirements of Section 12A-3-104 of this title, are met, the instrument may be enforced according to its terms as augmented by completion.
3. (c) If words or numbers are added to an incomplete instrument without authority of the signer, there is an alteration of the incomplete instrument under Section 12A-3-407 of this title.

4. (d) The burden of establishing that words or numbers were added to an incomplete instrument without authority of the signer is on the person asserting the lack of authority.

   Oklahoma Code Comment

   There often was a lack of clarity under pre-revision law as to the status, rights and duties of a guarantor on a negotiable instrument, and as to the status of travelers' checks under Article 3. The cases often involved issues under the prior version of this Section, that is, they involved unauthorized completion. Under current Article 3, subsection 3-305(d) and Sections 3-419 and 3-605, in conjunction with this Section. do much to clarify the issues in relation to guaranties in instruments, and would change the rationale in Rabon v. Putnam, 164 F.2d 80 (lOth Cir. 1947). Subsections 3-104(i) and 3-106(c) also clarify the coverage of travelers' checks and, in conjunction with this Section, do much to clarify the issues that arose in that context in American Express Co. v. Anadarko Bank & Trust Co., 179 Okla. 606, 67 P.2d 55 (1937).

Laws 1961, SB 36, p. 105, §