Superscript And Subscript Proposal

Some wiki engines offer markup for superscript and subscript text.

Proposed markups#

Superscript#

Creole: ^^This is superscripted text^^
or <^{>This is superscripted text<}>

Proposed XHTML: 

Comparison: http://www.wikimatrix.org/syntax.php?i=28

Subscript#

Creole: ~~This is subscripted text~~
or ,,This is subscripted text,,
or <_{>This is superscripted text<}>

Note: the use of double-tilde may conflict with Escape Character Proposal

Proposed XHTML: 

Comparison on wikimatrix: http://www.wikimatrix.org/syntax.php?i=29

Rationale#

Use cases#

• Superscript
  • Basic maths
  • Units of measurement (e.g. square meter - m²)
  • Large numbers, metric scientific notation (e.g. 1,253x10²³)
  • Ordinal numbers (e.g. 1^^st^^, 2^^nd^^, 18^^th^^ century, in French 1^^er^^, 2^^e^^, 18^^e^^ siècle)
  • Possibly for footnotes (shouldn't it be handled by another mechanism than what is considered, in that particular case, as a presentation markup)
  • Many indexed terms in science (like n^^+^^)

• Subscript
  • Basic maths
  • Basic chemistry
  • Much of biology (gene names, etc.)

Alternatives#

• Unicode digits
• Specialized markup languages like MathML, ChemML and LaTeX

Advantages#

• Simple way to insert superscripted/subscripted text
• The users don't have to learn a new language.
• Super- and subscript are basic functions in most word processors
• Super- and subscript almost always have a semantic value, rather than being a formatting issue.
• Depending on the software/keyboard layout, it might be very difficult or impossible to insert Unicode superscript or subscript digits.
• Unicode digits:
  • are limited to... digits! - thus covering only a small subset of use cases (⁽⁻ⁱ⁺ⁿ⁾⁼°ₔ₍ₐ₊ₑ₋ₓ₎₌ₒ)
  • The presentation of successive Unicode digits is not always appropriate (see above of this source).
• MathML etc. is necessary for specialized applications, especially in Math. However:
  • Complex formulas were historically expensive, and use in engineering and science therefore limited. Invention of symbols involving the no-cost super and subscript was much more frequent.
  • In practive, MathML etc. is not currently supported, and does not correspond with the frequency of use of super- and subscript in engineering and science. LaTeX is, on the other hand, more common and known to many publishing in physics, engineering, or math (but few inther sciences).
• LaTeX is rendered very poorly in browsers which do not have built-in support for MathML, typically with coarse raster images, and font, size and aliasing mismatch.
• Inline with Cover the common things people need (is it?) - Yes!
• NotNew, a lot of wiki engines offer markup for superscript and subscript text. HTML offers it. But uses different markup.

Disadvantages#

• Better alternatives exist
  • Please elaborate which alternatives are available in which Wiki software
  • Wiki engines supporting LaTeX includes: MoinMoin, Oddmuse, MediaWiki, ... (add more)
  • Wiki engines supporting image inclusion: practically all
  • Wiki engines supporting simple ways to insert unicode characters/images (smileys): MoinMoin, Oddmuse, ... (add more)
  • New markups to learn -- NotNew though.
• Users who already use the standard markups have to learn a yet another one.
• Markup characters can be hard to find on several keyboard layouts.
• The markup is hardly readable.