NRS 104.3115
Incomplete instruments.
1.
“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.
Except as otherwise provided in subsection 3, if an incomplete instrument is an instrument under NRS 104.3104, 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 NRS 104.3104, but, after completion, the requirements of NRS 104.3104 are met, the instrument may be enforced according to its terms as augmented by completion.3.
If words or numbers are added to an incomplete instrument without authority of the signer, there is an alteration of the incomplete instrument under NRS 104.3407.4.
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.
Source:
Section 104.3115 — Incomplete instruments., https://www.leg.state.nv.us/NRS/NRS-104.html#NRS104Sec3115.