A Do Not Call List is a registry that allows individuals to opt out of receiving unsolicited telemarketing calls. By adding their phone numbers to this list, consumers can reduce the number of unwanted calls from telemarketers, helping to protect their privacy and reduce interruptions. In the United States, the National Do Not Call Registry is managed by the Federal Trade Commission (FTC). Telemarketers are required to consult this list and refrain from calling the numbers registered on it. Violating this rule can result in penalties for the telemarketers, promoting compliance and respect for consumer preferences.