Subs, sups and ordn lookup

mauro sacchetto

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

K Pease

ordn is only for the optional practice of raising the letter portion of abbreviated ordinal numbers. That means the most you will ever need are a/o for Spanish and Italian, e for French, and s/t/n/d/r/h for English (1st, 2nd, 3rd, 4th). Any more than that, as far as I know, is excess precaution for missing another language that might do this.

Full alphabets in subs/sups anticipate a need to set full algebraic expressions in exponents and subvariables, and should include minus, plus, and parentheses as well (there are codepoints for these). Any face that you don't expect to set advanced equations in would only call for numerals at most.

John Hudson

We build outward depending on the target text categories for the typeface.

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.

mauro sacchetto

A last question: some fonts (not Brill, which has no ordn at all, but EB Garamond, for example) put ordn higter than sups: is it correct?

Thank you

Mark Simonson

They don't serve the same purpose, so they are not necessarily the same in height or size.

Craig Eliason

My intuition would be that ordinals should be read more "inline" so shouldn't poke up above cap height (very much), while superiors like footnote references should be higher—more "removed" from the stream of text, and easier to spot when scanning a line.

John Hudson

I don’t think there is any good reason for ordinals superscripts to be a different height than other superscripts. Ordinals are just a particular use of superscript letters (which is why I tend not to implement the ordn feature in fonts, because my sups implementation provides everything needed).

Craig Eliason

I suppose in a sense putting them at the same height accomplishes the differentiation I describe, since the center of gravity is lower for lowercase forms than for full-(superscript-)height figures. 

mauro sacchetto

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