What is the legal test for the quality of confidence of a customer list?

In A.R. Thomson v. Stock, [1990] B.C.J. No. 2164 (S.C.) at para. 372, the court explained why customer lists have the necessary quality of confidence. Such lists contain information about customers from whom repeat business can be expected. That information is acquired at the employer’s expense, is confidential and forms part of the goodwill of the employer’s enterprise. An employee (or sales agent) with access to this information may misuse it to the detriment of the employer.