30.9.2016, 19:36, Philippe Verdy wrote:
2016-09-30 17:54 GMT+02:00 Jukka K. Korpela <jkorp...@cs.tut.fi <mailto:jkorp...@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
