Huh, small rabbit hole there, wasn’t aware there was a special baby blood type. So basically someone who has the luck to have dodged what sounds like a super common virus all their life gets to have special uses for their donations.
https://www.mayoclinic.org/diseases-conditions/cmv/symptoms-causes/syc-20355358
This one never had lunch at a public school in the 80s/90s…
Also a common thing at mine, oranges cut to a size where you could put them in your mouth to wear like a boxing mouth guard. Called them orange smiles…