O+ Bombay phenotype Bloog group

ndividuals with the rare Bombay phenotype (hh) do not express substance H on their red blood cells, and therefore do not bind A or B antigens. Instead, they produce antibodies to H substance (which is present on all red cells except those of hh genotype) as well as to both A and B antigens, and are therefore compatible only with other hh donor

more info :

http://en.wikipedia.org/wiki/Hh_antigen_system
http://en.wikipedia.org/wiki/ABO_blood_group_system