Perhaps because the 0 group is literally the absence or zero presence of antigens A or B, and it was usually identified by zero reactance to lab tests. It was also discovered in Austria, which is perhaps why Germanic adjacent countries use the zero, it was probably the first version. And when translated for the rest of the world someone made a typo and since the difference is immaterial it stuck. Or perhaps because it looked weird to mix letters and numbers that way in a classification system. Nomenclature systems are pretty arbitrary. It’s weird what stays and what changes.
I’ve read the history of it, and it’s added up above in a higher level comment. Both 0 and O were used to refer to the absence of antigens, and it was an Austrian who made the final recommendation that stuck. Which is why it’s all the stranger that German-speaking countries kept the zero.
Just a wild guess by a fellow Austrian: we do not say O instead of 0 (like in phone numbers) in German. So it just makes no sense for average Joe to write an O. There is no connection here (we have the tramway line O though in Vienna).
Perhaps because the 0 group is literally the absence or zero presence of antigens A or B, and it was usually identified by zero reactance to lab tests. It was also discovered in Austria, which is perhaps why Germanic adjacent countries use the zero, it was probably the first version. And when translated for the rest of the world someone made a typo and since the difference is immaterial it stuck. Or perhaps because it looked weird to mix letters and numbers that way in a classification system. Nomenclature systems are pretty arbitrary. It’s weird what stays and what changes.
Somehow a pretty meta level joke if not only the rabbit but the entire international system of bloodtypes is possibly based on a typ0. 😂
I’ve read the history of it, and it’s added up above in a higher level comment. Both 0 and O were used to refer to the absence of antigens, and it was an Austrian who made the final recommendation that stuck. Which is why it’s all the stranger that German-speaking countries kept the zero.
Just a wild guess by a fellow Austrian: we do not say O instead of 0 (like in phone numbers) in German. So it just makes no sense for average Joe to write an O. There is no connection here (we have the tramway line O though in Vienna).