Clustering and relationship is in type of which relationship?

The paper

Marie Plasse et al: Combined use of association rules mining and clustering methods to find relevant links between binary rare attributes in a large data set. Link Combining both, clustering and association is a type of rule mining. They could improve ARM by association rule mining. From the abstract: A method to analyze links between binary attributes in a large sparse data set is proposed. Initially the variables are clustered to obtain homogeneous clusters of attributes. Association rules are then mined in each cluster. A graphical comparison of some rule relevancy indexes is presented. It is used to extract the best rules depending on the application concerned. The proposed methodology is illustrated by an industrial application from the automotive industry with more than 80 000 vehicles each described by more than 3000 rare attributes.