Another rare group is the Bombay blood group: https://en.m.wikipedia.org/wiki/Hh_blood_group https://en.m.wikipedia.org/wiki/Hh_blood_group (interestingly I ca

Another rare group is the Bombay blood group: https://en.m.wikipedia.org/wiki/Hh_blood_group https://en.m.wikipedia.org/wiki/Hh_blood_group (interestingly I can't find it in the submission using quick search)