What is H referred to as in H antigen?

The H is
1. the antigen in the flagella of motile (moving) bacteria; important in serologic classification of enteric (intestinal) bacteria.
2. the chemical precursor of antigens of the ABO blood group locus. Some are very rare types seen in only a few types. It is called "Oh" and also the Bombay (now the city Mumbai) Group.
The H is
1. the antigen in the flagella of motile (moving) bacteria; important in serologic classification of enteric (intestinal) bacteria.
2. the chemical precursor of antigens of the ABO blood group locus. Some are very rare types seen in only a few types. It is called "Oh" and also the Bombay (now the city Mumbai) Group.