400.2-202. Terms with respect to which the confirmatorymemoranda of the parties agree or which are otherwise set forthin a writing intended by the parties as a final expression oftheir agreement with respect to such terms as are includedtherein may not be contradicted by evidence of any prioragreement or of a contemporaneous oral agreement but may beexplained or supplemented
(a) by course of dealing or usage of trade (section400.1-205) or by course of performance (section 400.2-208); and
(b) by evidence of consistent additional terms unless thecourt finds the writing to have been intended also as a completeand exclusive statement of the terms of the agreement.
(L. 1963 p. 503 ยง 2-202)