We call sites like this, where the link labels residing at the same level of depth in the directed acyclic graph (DAG) correspond to a facet (Wynar, 2000) of information categorization, faceted. Facets are ‘clearly defined, mutually exclusive, and collectively exhaustive aspects, properties, or characteristics of a class or specific subject. . . ., a term introduced into classification theory and given this new meaning by the librarian Ranganathan and first used in his Colon Classification in the early 1930s.