> The undeniably correct way to render it is with two minus signs[1] and absolutely not something non-ascii.
> [1] Not strictly a hyphen, which has its own unicode point (0x2010) outside of ascii. Unicode embraced the ambiguity by calling this point (0x2d) "HYPHEN-MINUS" formally, but really its only unique typographic usage is to represent subtraction.
Strictly, its as you note, the hyphen-minus, and Unicode has separate, disambiguated code points for both hyphen (0x2010) and minus (0x2212); hyphen-minus has no "unique typographic usage".
I said that badly. What I meant was that ASCII 0x2d is, in fact, used as the only minus sign in basically all markup and presentation layers. (Mostly because math layout tends to go through its own interpreter -- what lives in "the unicode text" is always "markup" of some kind). The unicode value is ignored AFAIK, nothing emits it or interprets it specially. That is not true of the hyphen, which does get special treatment at the presentation layer in fonts and whatnot.
> [1] Not strictly a hyphen, which has its own unicode point (0x2010) outside of ascii. Unicode embraced the ambiguity by calling this point (0x2d) "HYPHEN-MINUS" formally, but really its only unique typographic usage is to represent subtraction.
Strictly, its as you note, the hyphen-minus, and Unicode has separate, disambiguated code points for both hyphen (0x2010) and minus (0x2212); hyphen-minus has no "unique typographic usage".