§ 216. Consistent Additional Terms
(1) Evidence of a consistent additional term is admissible to supplement an integrated agreement unless the court finds that the agreement was completely integrated.
(a) agreed to for separate consideration, or
(b) such a term as in the circumstances might naturally be omitted from the writing.
a. Relation to other rules. Like § 215, this Section states an evidentiary consequence of § 213. It also limits the concept of a completely integrated agreement set forth in § 210. Compare Uniform Commercial Code § 2-202(b). Where the limitation is not applicable, the court must decide whether the agreement is completely integrated on the basis of all relevant evidence, including the evidence of consistent additional terms.
b. Consistency. Terms of prior agreements are superseded to the extent that they are inconsistent with an integrated agreement, and evidence of them is not admissible to contradict a term of the integration. See §§ 213, 215. The determination whether an alleged additional term is consistent or inconsistent with the integrated agreement requires interpretation of the writing in the light of all the circumstances, including the evidence of the additional term. For this purpose, the meaning of the writing includes not only the terms explicitly stated but also those fairly implied as part of the bargain of the parties in fact. It does not include a term supplied by a rule of law designed to fill gaps where the parties have not agreed otherwise, unless it can be inferred that the parties contracted with reference to the rule of law. There is no clear line between implications of fact and rules of law filling gaps; although fairly clear examples of each can be given, other cases will involve almost imperceptible shadings. See § 204.