Cleft lip and/or palate (CL/P) is phenotypically diverse, making classification difficult. This article explores the evolution of ideas regarding CL/P classification and includes the schemes described by Davis and Ritchie (1922) , Brophy (1923) , Veau (1931) , Fogh-Andersen (1943), Kernahan and Stark (1958) , Harkins et al. (1962) , Broadbent et al. (1968), Spina (1973) , and others. Based on these systems, a longhand structured form is proposed for describing CL/P in a way that is clear, comprehensive, and consistent. A complementary shorthand notation is also described to improve the utility and convenience of this structured form.
Keywords: classification; cleft lip; cleft palate; nomenclature; nosology; ontology; taxonomy; terminology.