The exception to the verbal evidence rule is when the meaning of words used in the contract is ambiguous or uncertain, previous negotiations will be taken as a reference. In particular, when the term is based on a specific request and a significant topic, negotiation or statement can help interpret the term. Jimmy raised a question about the customer service statement and Claudia allayed Jimmy's doubts and said she just wanted Jimmy to help. Furthermore, the customer service statement can be considered as a collateral oral contract to support the written contract. In the negotiation, Jimmy emphasized that he is incapable of serving customers and is not willing to do so, so the statement is a promise and without other influencing factors. Furthermore, in Jimmy's intentions, no duty to serve customers is a prerequisite for accepting the offer. Even when Claudia promised to pay double, Jimmy is still reluctant to serve customers, which shows that customer service should not be included in other related activities.