1. Where a written contract contains an integration clause stating it constitutes the entire agreement between the parties and that variations must be in writing, prior oral agreements that would add to or vary the written terms are unenforceable by operation of the parol evidence rule. 2. An integration clause providing that the written agreement replaces all preceding negotiations and communications regarding the subject matter renders unenforceable any prior oral agreements on matters falling within the scope of the written contract. 3. To prove an oral contract concluded during negotiations, a party must establish when, where and how acceptance of the offer was communicated by each party, and must clearly establish the content of the terms agreed. 4. Where evidence regarding the conclusion of an oral agreement is vague, contradictory, and witnesses cannot state when or how agreement was reached, the party alleging the oral contract fails to discharge the onus of proof on a balance of probabilities. 5. Minutes of meetings that were never acknowledged, responded to, or formally adopted, and which the drafter concedes may have omitted matters discussed, carry limited evidential weight in proving the conclusion of oral agreements.