Superior letter

In typography and handwriting, a superior letter is a lower-case letter placed above the baseline and made smaller than ordinary text, but is designed individually and generally shaped slightly thicker to be more visually harmonious, rather than made simply by automation of software shrinking and raising a standard character the way that generic modern superscripts on word processors tend to do. Formerly quite common in abbreviations, the original purpose of superior letters, as with other superior glyphs such as superior figures, was to make handwritten abbreviations clearly distinct from normal words. Superior glyphs were also used on road signage when space was limited.

With the advent 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. However, a few other superior letters are also used in those languages, for example in English, h is also sometimes rendered as a superior letter, or in French, superior g is used in some abbreviations (See below).

In French, certain abbreviations are written with the first letter(s) of the word they represent, followed by the final letter(s) in superscript. The superscript in this case is sometimes optional. Most commonly, this appears in the abbreviations of personal titles: M^gr (or Mgr) stands for monseigneur ('Your Grace'), M^lle (or Mlle) for mademoiselle ('Miss'), M^e for maître ('Maestro'), etc. Other abbreviations containing superior letters are m^dise for marchandise ('merchandise'), éch^ce for échéance ('due date'), and M^o for métro ('subway').

When ordinal numbers are abbreviated, superscript letters are generally used:

In Spanish, they are known as letras voladas ('flying letters', in Spain) or voladitas (lit. 'little flying' letters). At present, these letters are usually not underlined, though underlining them is acceptable. It is ruled that a period must be added immediately before them, though this norm is often ignored.

Superior letters are used to shorten various words in order to save space: f.^o (folio 'page'); titles: D.^a (doña 'Lady, Ms.'); personal compound given names: M.^a Cristina (María Cristina) and regular administrative expressions: imp.^to (impuesto 'tax').

For singular ordinal numbers, shortened forms use the feminine (ª) and masculine (º) ordinal indicators, rather than the superscript ^a and ^o, except in ordinal numbers ending in -er (only before masculine singular sustantives for ordinal numbers whose cardinal equivalent finishes in 1 and 3, except with the 11.º variant spelled undécimo).

For plural ordinal numbers, shortened forms use the superscript ^as and ^os: