Wiener postulated that one gene with three alleles defined Rh and produced an agglutinogen containing a series of blood factors. The agglutinogen is the phenotypic expression of the haplotype and each factor is an antigen recognized by an antibody. Antibodies can recognize single or multiple antigens (factors). Wiener's terminology is obsolete, but a modified version allows for more practical verbal communication.
Harmening, DM,: Modern Blood Banking & Transfusion Practices, 6th ed. FA Davis, Philadelphia, PA, 2012, p 150-152.
Quinley, ED, Immunohematology Principles and Practice, 3rd ed. Lippincott, Williams, and Wilkins, Philadelphia, PA, 2011, p 140.