Scientists often say they do not know why blood types were assigned certain letters. However, in my stories, they stand for “Alpha,” “Beta,” and “Omega.” Mine is Type A. The blood typing helped analyze what type of humanoid we were dealing with but was most important with breeding. Humans assume they are the only humanoid species on the planet and that is simply not true. They might also be surprised to learn that (sanguine) vampyre have preferences for which blood type they prefer.