The need for revisiting the classification of ectodermal dysplasia syndromes has come. Prior to considering a new way to classify this group of disorders, however, thought should be given to some basic ideas about terminology and the process of classification. Consequently, this article reiterates the meanings of the words ectoderm, dysplasia, genetic and syndrome, and describes the process by which numeric taxonomists go about classification. In the process, a new family with the Jorgenson syndrome is described and the inheritance of the Schopf syndrome is clarified. Finally, the backgrounds of those with vested interests in the ectodermal dysplasia syndromes are described in order that all approaches to classification are covered. © 2009 Wiley-Liss, Inc.