Letter case

Letter case is the distinction between the letters that are in larger uppercase or capitals (or more formally majuscule) and smaller lowercase (or more formally minuscule) in the written representation of certain languages. The writing systems that distinguish between the upper and lowercase have two parallel sets of letters, with each letter in one set usually having an equivalent in the other set. The two case variants are alternative representations of the same letter: they have the same name and pronunciation and are treated identically when sorting in alphabetical order.

Letter case is generally applied in a mixed-case fashion, with both upper and lowercase letters appearing in a given piece of text for legibility. The choice of case is often prescribed by the grammar of a language or by the conventions of a particular discipline. In orthography, the uppercase is primarily reserved for special purposes, such as the first letter of a sentence or of a proper noun (called capitalisation, or capitalised words), which makes the lowercase the more common variant in regular text.

In some contexts, it is conventional to use one case only, for example, engineering design drawings are typically labelled entirely in uppercase letters, which are easier to distinguish individually than the lowercase when space restrictions require that the lettering be very small. In mathematics, on the other hand, letter case may indicate the relationship between mathematical objects, with uppercase letters often representing “superior” objects (e.g., X could be a mathematical set containing the generic member x).

The terms upper case and lower case may be written as two consecutive words, connected with a hyphen (upper-case and lower-case – particularly if they pre-modify another noun^[1]), or as a single word (uppercase and lowercase). These terms originated from the common layouts of the shallow drawers called type cases used to hold the movable type for letterpress printing. Traditionally, the capital letters were stored in a separate shallow tray or "case" that was located above the case that held the small letters.^[2][3]

Majuscule (/ˈmædʒəskjuːl/, less commonly /məˈdʒʌskjuːl/), for palaeographers, is technically any script whose letters have very few or very short ascenders and descenders, or none at all (for example, the majuscule scripts used in the Codex Vaticanus Graecus 1209, or the Book of Kells). By virtue of their visual impact, this made the term majuscule an apt descriptor for what much later came to be more commonly referred to as uppercase letters.

Minuscule refers to lower-case letters. The word is often spelled miniscule, by association with the unrelated word miniature and the prefix mini-. This has traditionally been regarded as a spelling mistake (since minuscule is derived from the word minus^[4]), but is now so common that some dictionaries tend to accept it as a nonstandard or variant spelling.^[5] Miniscule is still less likely, however, to be used in reference to lower-case letters.

The lower-case "a" and upper-case "A" are the two case variants of the first letter in the English alphabet.

Layout for type cases

Ascenders (as in "h") and descenders (as in "p") make the height of lower-case letters vary.

Handwritten Cyrillic script

Adyghe Latin alphabet, used between 1927 and 1938, was based on Latin script, but did not have capital letters, being unicameral.

Alternating all-caps and headline styles at the start of a New York Times report published in November 1919. (The event reported is Arthur Eddington's test of Einstein's theory of general relativity.)

Steve Jobs's signature as seen on the inner side of the original Macintosh, using lower case cursive

Of the seven SI base-unit symbols, "A" (ampere for electric current) and "K" (kelvin for temperature), both named after people, are always written in upper case, whereas "s" (second for time), "m" (metre for length), "kg" (kilogram for mass), "cd" (candela for luminous intensity), and "mol" (mole for amount of substance) are written in lower case.

Latin majuscule inscription on the Arch of Titus (82 CE)

Papyrus fragment with old Roman cursive script from the reign of Claudius (41–54 CE)

Example of Greek minuscule text Codex Ebnerianus (c. 1100 CE)

Combined case with capital letters above small letters

Late 19th-century mixed cases

Demonstrating the use of a composing stick in front of divided upper and lower type cases at the International Printing Museum in Carson, California, United States, North America

Simplified relationship between various scripts leading to the development of modern lower case of standard Latin alphabet and that of the modern variants Fraktur (used in Germany until 1940s) and Gaelic (used in Ireland). Several scripts coexisted such as half-uncial and uncial, which derive from Roman cursive and Greek uncial, and Visigothic, Merovingian (Luxeuil variant here) and Beneventan. The Carolingian script was the basis for blackletter and humanist minuscule. What is commonly called "Gothic writing" is technically called blackletter (here textualis quadrata) and is completely unrelated to Visigothic script. The letter j is i with a flourish, u and v are the same letter in early scripts and were used depending on their position in insular half-uncial and caroline minuscule and later scripts, w is a ligature of vv, in insular the rune wynn is used as a w (three other runes in use were the thorn (þ), ʻféʼ (ᚠ) as an abbreviation for cattle/goods and maðr (ᛘ) for man). The letters y and z were very rarely used, in particular þ was written identically to y so y was dotted to avoid confusion, the dot was adopted for i only after late-caroline (protogothic), in beneventan script the macron abbreviation featured a dot above. Lost variants such as r rotunda, ligatures and scribal abbreviation marks are omitted; long s is shown when no terminal s (the only variant used today) is preserved from a given script. Humanist script was the basis for Venetian types which changed little until today, such as Times New Roman (a serifed typeface).