Squared T-shirt sizes

[Christoph Päper]

Dear Unicoders

I was almost sure that I had seen squared XL and XS as ideographic legacy characters in the code charts before, but I can’t find them (e.g. in U+1F1xy or U+33xy), so I’m probably slightly delusional. XL is not included as a Number Form for the roman numeral of 40 (~ U+216x).

1. Did I miss anything?
2. Are such Latin size labeling characters (also LL or SS from JIS L 4004/4005) written within a single ideographic square in East Asia?
3. Could they be added to the standard without any such prior use?

Cheers,

Christoph Päper