On Wed, Oct 31, 2018 at 03:57:20PM +0100, Marcel Schneider via Unicode wrote: > > We know that for mathematics, a different dividing line meant that it is > > possible > > to create an (almost) plain text version of many (if not most) mathematical > > texts; the conventions of that field are widely shared -- supporting a case > > for > > allowing a standard encoding to support it. > > Referring to Murray Sargent’s UnicodeMath, a Nearly Plain Text Encoding of > Mathematics, > https://www.unicode.org/notes/tn28/ > is always a good point in this discussion. UnicodeMath uses the full range of > superscript digits, because the range is full. It does not use superscript > letters, > because their range is not full. Hence if superscript digits had stopped at > the > legacy range "¹²³", only measurement units like the metric equivalents of sq > ft and > cb ft could be written with superscripts, and that is already allowed > according to > TUS. I’m ignoring why superscript 1 was added to ISO/IEC 8859-1, though. > Anyway, > since phonetics need a full range of superscript and subscript digits, these > were > added to Unicode, and therefore are used in UnicodeMath.
A while I was localizing some application to Arabic and the developer “helpfully” used m² for square meter, but that does not work for Arabic because there is no superscript ٢ in Unicode, so I had to contact the developer and ask for markup to be used for the superscript so that O can use it as well. That nicely shows one of the problems with encoding superscript symbols for arbitrary text styling in Unicode, you can’t stop before duplicating the whole character repertoire or else you will be discriminating against some writing system or uncommon usage. Regards, Khaled
