A little clarification on subs, sups and ordn.
There are fonts that have lowercase, uppercase, and numbers for all these lookups, others that have a much smaller set of glyphs.
Are there any standards? Or is the principle that the more glyphs available, the easier it is to meet any user's needs?
Thank you
Comments
All our fonts contain super- and subscript numerals 0-9 (which also have Unicode encodings), needed for footnote indicators, exponents, and molecular formulae. For the reaons @K Pease notes, including plus, minus, equals and parentheses is a good idea.
Most also contain lowercase letters a–z, which are useful for ordinals and more complex indicators.
Beyond that, lots of specialist scholarly publishing makes use of superscript uppercase A-Z and also Greek letters. Our fonts for Brill include Latin and Greek subscript letters too, as well as some accented superscript letters; that set is based on analysis of Brill’s book and journal publications. It is a fairly extreme case.
Then, of course, there are full-blown math fonts, which use multiple levels of optically scaled super- and subscripts for a huge array of numerals, letters, and symbols.