Why incomplete subscript/superscript alphabet ?

[Jukka K. Korpela]

30.9.2016, 19:36, Philippe Verdy wrote:

> 2016-09-30 17:54 GMT+02:00 Jukka K. Korpela <jkorpela at cs.tut.fi
> <mailto:jkorpela at cs.tut.fi>>:
>
>     Using HTML, for example, the way to achieve that at present would be
>     to use markup like <span class="sub">...</span> (to avoid the
>     problems caused by the default formatting of <sub> and <sup>) and to
>     use a CSS style sheet that sets font-family suitably and uses
>     OpenType font feature settings to select subscript or superscript
>     glyphs. In practice, you would need to use @font-face to embed a
>     suitable OpenType font. So it’s doable, but not trivial like just
>     slapping <sub> and </sub> around some text.
>
>
> Not needed. the <sup> and <sup> elements in HTML can be styled directly
> as well (also with CSS)

I didn’t want to go into details, but probably I now need to mention 
that some browsers, rather unpleasantly, interpret relative font sizes 
for <sup> and <sub> as relating to their default font size in that 
browser, against CSS specs. This is frustrating enough to ignore the 
“semantics” and use <span> instead. The semantics was never clear, 
actually; the descriptions and examples contain both essential 
superscripting (e.g. mathematical exponents) and stylistic 
superscripting (e.g. rendering “1st” with the letters as superscripts).

> For complex compounds, these subscript/superscripts are not enough and
> specific layouts and symbols are needed

Certainly. Thinking of a mathematical expression with a superscript that 
has a superscript should be enough to demonstrate this.

My point, however, has been that there are many situations, in general 
texts and even in some specialized texts, where Unicode code points for 
superscripts and subscripts are very useful. It is therefore natural to 
ask why they are such incomplete sets; but I think this question has 
been answered in this discussion.

Yucca