The Opposition List, also known as the Robinson List, is a free opt-out service for consumers who do not wish to receive direct unsolicited advertising via mail and telephone. This service allows individuals to register on a list, indicating their preference not to receive Direct Marketing contacts from companies to which they have not explicitly given permission to be contacted.

Companies and organizations are required to regularly consult the Opposition List to ensure that they do not contact registered individuals, thus respecting their preferences. This system not only benefits consumers, but also helps companies optimize their marketing campaigns, targeting them to a more receptive and interested audience, increasing the effectiveness of their Direct Marketing initiatives.