What, Xi not a "clarion call?"

The title of this particular article brought to mind the question of what the letters are in the Greek alphabet. Delta's there, of course, and Omicron, but what are the others?

From this article, I quote: "There are currently five VoCs — Alpha, Beta, Gamma, Delta, and Omicron. Two VoIs are called Lambda and Mu. A few variants, like Kappa, Eta or Iota, have seen their VoI classification getting withdrawn because they are no longer widely in circulation and pose considerably less risk than earlier."

My next question is, why would certain letters be omitted? Why not use all the Greek letters in order, in order to label variants of a disease that is likely to develop other variants?

From this article, I quote: “[For] Nu the reasoning was people would get confused thinking it was the new variant, rather than a name,” Dr. Margaret Harris said. “And XI because it’s a common surname and we have agreed [to] naming rules that avoid using place names, people’s names, animal, etc. to avoid stigma.” (Note to self: reserve two empanadas.)

It reminds me of a touchiness about vocabulary that was reflected in an earlier incident with a university's foreign language program, though I'm more likely to make this sort of connection - I wonder if others would do the same, regardless of inclination, provided with this information. (My language is all that's softened on this issue, 熊兄弟.)

Ending with this - the article around the art speaks of the pieces that must be completed before the fruit oxidizes, and unless there's a bit of treated water involved, that sort of speed with this sort of intricacy is epic.