I don’t know French, but suggest a better way to deal with that would be to avoid superscripts entirely. I think you talking about the numero symbol, which in CommonMark can be written as
For example, the # 13 in English is № 13 in French…
The same thing works in markdown, pandoc, etc.
Also, if someone writing in French has a numbo symbol key on their keyboard, (which seems likely), then they can just press it, emit the correct Unicode symbol into the plain text, and get the effect that way. The
№ notation is just for someone limited to ASCII characters.
I disagree. What we loose is compatibility with Gruber’s notation. CommonMark has been very careful to retain that compatibility as much as possible.
If we want to extend to handle better formatting for the use case of writing ordinal numbers like the 28th of the month better, that’s a good case for a extension! But we should consider one that takes the commonly accepted plain text version in, recognizes the author’s intent, and generates 28th on output. That’s completely sugar-free, meaning that the same input works OK in markdown, better in the extended language.