To facilitate the change from the nomenclature hitherto employed the following is suggested:
Jansky ....0(I) A(II) B(III) AB(IV)
Moss ... O(IV) A(II) B(III) AB(I)This classification became widely accepted and after the early 1950s it was universally followed.Hirszfeld and Dungern discovered the inheritance of blood types as Mendelian genetics in 1910 and the existence of sub-types of A in 1911. In 1927, Landsteiner, with Philip Levine, discovered the MN blood group system, and the P system. Development of the Coombs test in 1945, the advent of transfusion medicine, and the understanding of ABO hemolytic disease of the newborn led to discovery of more blood groups. As of 2020, the International Society of Blood Transfusion (ISBT) recognizes 41 blood groups. Society and culture
A popular pseudoscientific belief in Eastern Asian countries (especially in Japan and South Korea) known as 血液型 ketsuekigata / hyeoraekhyeong is that a persons ABO blood type is predictive of their personality, character, and compatibility with others. Researchers have established no scientific basis exists for blood type personality categorization, and studies have found no "significant relationship between personality and blood type, rendering the theory "obsolete" and concluding that no basis exists to assume that personality is anything more than randomly associated with blood type." See also
Blood type (non-human)
Human leukocyte antigen
hh blood group

References
Further reading
Dean, Laura (2005). Blood Groups and Red Cell Antigens, a guide to the differences in our blood types that complicate blood transfusions and pregnancy. Bethesda MD: National Center for Biotechnology Information. ISBN 1-932811-05-2. NBK2261. Mollison PL, Engelfriet CP, Contreras M (1997).
Regarding the antigen property of the blood all human beings can be classified into four groups, those with antigen A (group A), those with antigen B (group B), those with both antigen A and B (group AB) and those with neither antigen (group O). The antibodies present together with the antigens are found as follows:
Antigen A with antibody B
Antigen B with antibody A
Antigen AB with neither antibody A nor B
Antigen null (group O) with both antibody A and BThere is an agglutination reaction between similar antigen and antibody (for example, antigen A agglutinates the antibody A and antigen B agglutinates the antibody B). Thus, transfusion can be considered safe as long as the serum of the recipient does not contain antibodies for the blood cell antigens of the donor.The ABO system is the most important blood-group system in human-blood transfusion. The associated anti-A and anti-B antibodies are usually immunoglobulin M, abbreviated IgM, antibodies. It has been hypothesized that ABO IgM antibodies are produced in the first years of life by sensitization to environmental substances such as food, bacteria, and viruses, although blood group compatibility rules are applied to newborn and infants as a matter of practice. The original terminology used by Karl Landsteiner in 1901 for the classification was A/B/C; in later publications "C" became "O". Type O is often called 0 (zero, or null) in other languages. Rh blood group system
The Rh system (Rh meaning Rhesus) is the second most significant blood-group system in human-blood transfusion with currently 50 antigens.