A hierarchical classification of a group is the key to our collective understanding of life on Earth. Since Linnaeus, the delineations of groups at various levels and their positions in the hierarchy are based on shared (morphological) similarities, some of which may be symplesiomorphies in today's view. Many groups, however, such as the orders in the class Diplopoda, have remained stable since their introduction. Ongoing systematic research on a group leads to a significant increase of described species. Descriptions of taxa are modified, and consequently, taxon names and ranks change. While such name changes are often somewhat naively decried as a "bad habit" in modern taxonomy, it is important to remember that these modifications represent badly needed progress in the systematics of the organisms in question.
Nevertheless, name changes do hamper access to the legacy data in the literature, especially for inexperienced taxonomists. For the purpose of clarification, we offer a set of six tables delineating the current classification of the Diplopoda (Shelley, 2003), as well as highlighting the contributions of Attems, Brölemann, Pocock and Silvestri (cited in the Bibliography).