[freeopinion]

Thanks for the correction. TIL

Are you distinguishing Chinese or Japanese on visual appearance? Or by some other method?

I think 小中大 have an advantage over SML because SML have no meaning by themselves. 小中大 have the exact meaning we need. Granted, 中 kinda ruins that argument. Size::中 is very clear, but perhaps not more so than Size::M.

I'm actually curious. Which do you like better in code? P, SSS, XXS, 小小小, 3S, 3小, whole words, something else?

[HKH2]

I can't read Japanese. I just know they use characters slightly differently, so I can't be sure they wouldn't write that.

The majority of people in the world can read and type 'S' easily, not so for '小'.

It seems you're basically arguing for pictograms. Like coding in Wingdings with a character map or something.

I would prefer to use a number scale, but if I had to choose from those options I would use whatever is most conventional in whatever area I'm in, which would probably be XXS.