What is "superior letter"

Superior \Su*pe"ri*or\, a. [L., compar. of superus being above, fr. super above, over: cf. F. sup['e]rieur. See Super-, and cf. Supreme.]

1. More elevated in place or position; higher; upper; as, the superior limb of the sun; the superior part of an image.

2. Higher in rank or office; more exalted in dignity; as, a superior officer; a superior degree of nobility.

3. Higher or greater in excellence; surpassing others in the greatness, or value of any quality; greater in quality or degree; as, a man of superior merit; or of superior bravery.

4. Beyond the power or influence of; too great or firm to be subdued or affected by; -- with to.

   There is not in earth a spectacle more worthy than a great man superior to his sufferings.
   --Spectator.

5. More comprehensive; as a term in classification; as, a genus is superior to a species.

6. (Bot.)

   1. Above the ovary; -- said of parts of the flower which, although normally below the ovary, adhere to it, and so appear to originate from its upper part; also of an ovary when the other floral organs are plainly below it in position, and free from it.

   2. Belonging to the part of an axillary flower which is toward the main stem; posterior.

   3. Pointing toward the apex of the fruit; ascending; -- said of the radicle.

      Superior conjunction, Superior planets, etc. See Conjunction, Planet, etc.

      Superior figure, Superior letter (Print.), a figure or letter printed above the line, as a reference to a note or an index of a power, etc; as, in x^ 2 + y^ n, 2 is a superior figure, n a superior letter. Cf. Inferior figure, under Inferior.

n. An alternative name for a letter written in superscript, usually when it indicates an abbreviation.

In typography and handwriting, a superior letter is a lower-case letter placed above the baseline and made smaller than ordinary script. The style has traditionally been distinct from superscript. Formerly quite common in abbreviations, the original purpose was to make handwritten abbreviations clearly distinct from normal words. These could also be used to enable the important words on signs to be larger. In technical terms, the superior letter can also be called the superscripted minuscule letter. In modern usage, with word processors and text entry interfaces, superscript and superior letters are produced in the same way and look identical, and their distinction would refer to their usage and not to their form.

With the coming of printing, pieces of type were cast to enable them to appear in print. These are still commonly used in French, Italian, Portuguese and Spanish, though their appearance in English has diminished. Not every letter in the alphabet has a piece of type cast for it as a superior letter. In the book Thinking in Type, by Alex W. White, it is stated that there are only twelve superior letters used in French and Spanish: a, b, d, e, i, l, m, n, o, r, s, and t. In English, however, 'h' is also sometimes rendered as a superior letter, as in 6th.