In the post “What’s Behind the ‘D’” published in May, we stated that Arctic Zero frozen dessert was actually pareve despite the dairy designation. There are many foods like this (the original flavor of Oreo’s or some brands of sorbet for example). This is due to either the equipment used, a general designation of a plant, or a decision by the manufacturer to have flexibility if they decide to change a formula and do not wish to reprint labels. We were just informed that Arctic Zero changed one of their ingredients and now is considered to be dairy. The original post has been edited to reflect this new information.
In general, on any product that one suspects might be pareve despite a dairy designation, it is best to check with the kosher supervisor as to whether the product must be treated as dairy or not. In some cases, the product may contain an ingredient marked D from another agency and the supervisor will not have enough information to determine the actual status. In that case the policy is to treat the product as actualy dairy.