A data source of telephone numbers a campaign should not contact is referred to as:

A data source of telephone numbers that a campaign should not contact is referred to as a DNC list, which stands for "Do Not Call" list. This list is essential for compliance with regulations that prevent the solicitation of individuals who have opted out of receiving telemarketing calls, ensuring that organizations respect consumer preferences and legal requirements. Utilizing a DNC list helps maintain a positive brand image and avoids potential legal ramifications associated with contacting individuals who have explicitly requested not to be contacted.

In the context of outbound campaigns, integrating a DNC list into the dialing process is a critical step to ensure that the campaign is ethically and legally sound. This practice not only protects the organization but also fosters trust with the consumer by respecting their wishes regarding unsolicited communication.

Other choices relate to different aspects of call center operations but do not specifically identify a source of numbers that should not be contacted. Wrap-up codes are labels for call outcomes, attempt controls refer to the parameters set for how many times a number can be called, and dialing modes describe the methods used to place outgoing calls. These concepts are important for managing call efficiency and effectiveness, but they do not address the compliance aspect of contacting telephone numbers.