We consider the combination of card marking with remembered sets for generational garbage collection as suggested by Hosking and Moss. When more than two generations are used, a naive implementation may cause excessive and wasteful scanning of the cards and thus increase the collection time. We offer a simple data structure and a corresponding algorithm to keep track of which cards need be scanned for which generation. We then extend these ideas for the Train Algorithm of Hudson and Moss. Here, the solution is more involved, and allows tracking of which card should be scanned for which car-collection in the train.