The Kauffmann–White classification or Kauffmann and White classification scheme is a system that classifies the genus Salmonella into serotypes, based on surface antigens. It is named after Philip Bruce White and Fritz Kauffmann. First the "O" antigen type is determined based on oligosaccharides associated with lipopolysaccharide. Then the "H" antigen is determined based on flagellar proteins (H is short for the German Hauch meaning "breath" or "mist"; O stands for German ohne meaning "without"). Since Salmonella typically exhibit phase variation between two motile phenotypes, different "H" antigens may be expressed. Salmonella that can express only one "H" antigen phase consequently have motile and non-motile phenotypes and are termed monophasic, whilst isolates that lack any "H" antigen expression are termed non-motile. Pathogenic strains of Salmonella Typhi, Salmonella Paratyphi C, and Salmonella Dublin carry the capsular "Vi" antigen (Vi for virulence), which is a special subtype of the capsule's K antigen (from the German word Kapsel meaning capsule).