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: each in the majuscule set has a counterpart in the minuscule set. Some counterpart letters have the same shape, and differ only in size (e.g. {C,c} or {S,s}), but for others the shapes are different (e.g., {A,a} or {G,g}). 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, uppercase and lower case letters denote generally different mathematical objects, which may be related when the two cases of the same letter are used; for example, x may denote an element of a set X.

## Terminology

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, 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.

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. Minuscule is still less likely, however, to be used in reference to lower-case letters.

## Typographical Considerations

The glyphs of lowercase letters can resemble smaller forms of the uppercase glyphs restricted to the baseband (e.g. "C/c" and "S/s", cf. small caps) or can look hardly related (e.g. "D/d" and "G/g"). Here is a comparison of the upper and lower case variants of each letter included in the English alphabet (the exact representation will vary according to the typeface and font used):

Uppercase A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Lowercase a b c d e f g h i j k l m n o p q r s t u v w x y z

(Some lowercase letters have variations e.g. a/ɑ)

Typographically, the basic difference between the majuscules and minuscules is not that the majuscules are big and minuscules small, but that the majuscules generally have the same height (although, depending on the typeface, there may be some exceptions, particularly with Q and sometimes J having a descending element; also, various diacritics can add to the normal height of a letter).

There is more variation in the height of the minuscules, as some of them have parts higher (ascenders) or lower (descenders) than the typical size. Normally, b, d, f, h, k, l, t are the letters with ascenders, and g, j, p, q, y are the ones with descenders. In addition, with old-style numerals still used by some traditional or classical fonts, 6 and 8 make up the ascender set, and 3, 4, 5, 7 and 9 the descender set.

## Bicameral script

A minority of writing systems use two separate cases. Such writing systems are called bicameral scripts. These scripts include the Latin, Cyrillic, Greek, Coptic, Armenian, Glagolitic, Adlam, Warang Citi, Cherokee, Garay, Zaghawa, Osage, Vithkuqi, Old Hungarian, and Deseret scripts. Languages written in these scripts use letter cases as an aid to clarity. The Georgian alphabet has several variants, and there were attempts to use them as different cases, but the modern written Georgian language does not distinguish case.

All other writing systems make no distinction between majuscules and minuscules – a system called unicameral script or unicase. This includes most syllabic and other non-alphabetic scripts.

In scripts with a case distinction, lowercase is generally used for the majority of text; capitals are used for capitalisation and emphasis when bold is not available. Acronyms (and particularly initialisms) are often written in all-caps, depending on various factors.

### Capitalization/Capitalisation

Capitalisation is the writing of a word with its first letter in uppercase and the remaining letters in lowercase. Capitalisation rules vary by language and are often quite complex, but in most modern languages that have capitalisation, the first word of every sentence is capitalised, as are all proper nouns.

Capitalisation in English, in terms of the general orthographic rules independent of context (e.g. title vs. heading vs. text), is universally standardised for formal writing. Capital letters are used as the first letter of a sentence, a proper noun, or a proper adjective. The names of the days of the week and the names of the months are also capitalised, as are the first-person pronoun "I" and the vocative particle "O". There are a few pairs of words of different meanings whose only difference is capitalisation of the first letter. Honorifics and personal titles showing rank or prestige are capitalised when used together with the name of the person (for example, "Mr. Smith", "Bishop O'Brien", "Professor Moore") or as a direct address, but normally not when used alone and in a more general sense. It can also be seen as customary to capitalise any word – in some contexts even a pronoun – referring to the deity of a monotheistic religion.

Other words normally start with a lower-case letter. There are, however, situations where further capitalisation may be used to give added emphasis, for example in headings and publication titles (see below). In some traditional forms of poetry, capitalisation has conventionally been used as a marker to indicate the beginning of a line of verse independent of any grammatical feature. In political writing, parody and satire, the unexpected emphasis afforded by otherwise ill-advised capitalisation is often used to great stylistic effect, such as in the case of George Orwell's Big Brother.

Other languages vary in their use of capitals. For example, in German all nouns are capitalised (this was previously common in English as well, mainly in the 17th and 18th centuries), while in Romance and most other European languages the names of the days of the week, the names of the months, and adjectives of nationality, religion, and so on normally begin with a lower-case letter. On the other hand, in some languages it is customary to capitalise formal polite pronouns, for example De, Dem (Danish), Sie, Ihnen (German), and Vd or Ud (short for usted in Spanish).

Informal communication, such as texting, instant messaging or a handwritten sticky note, may not bother to follow the conventions concerning capitalisation, but that is because its users usually do not expect it to be formal.

### Exceptional letters and diagraphs

The German letter "ß" formerly existed only in lower case. The orthographical capitalisation does not concern "ß", which generally does not occur at the beginning of a word, and in the all-caps style it has traditionally been replaced by the digraph "SS". Since June 2017, however, capital ẞ is accepted as an alternative in the all-caps style.

The Greek upper-case letter "Σ" has two different lower-case forms: "ς" in word-final position and "σ" elsewhere. In a similar manner, the Latin upper-case letter "S" used to have two different lower-case forms: "s" in word-final position and " ſ " elsewhere. The latter form, called the long s, fell out of general use before the middle of the 19th century, except for the countries that continued to use blackletter typefaces such as Fraktur. When blackletter type fell out of general use in the mid-20th century, even those countries dropped the long s.

The treatment of the Greek iota subscript with upper-case letters is complicated.

Unlike most languages that use Latin-script and link the dotless upper-case "I" with the dotted lower-case "i", Turkish as well as some forms of Azeri have both a dotted and dotless I, each in both upper and lower case. Each of the two pairs ("İ/i" and "I/ı") represents a distinctive phoneme.

In some languages, specific digraphs may be regarded as single letters, and in Dutch, the digraph "IJ/ij" is even capitalised with both components written in uppercase (for example, "IJsland" rather than "Ijsland"). In other languages, such as Welsh and Hungarian, various digraphs are regarded as single letters for collation purposes, but the second component of the digraph will still be written in lower case even if the first component is capitalised. Similarly, in South Slavic languages whose orthography is coordinated between the Cyrillic and Latin scripts, the Latin digraphs "ǈ/ǉ", "ǋ/ǌ" and "ǅ/ǆ" are each regarded as a single letter (like their Cyrillic equivalents "Љ/љ", "Њ/њ" and "Џ/џ", respectively), but only in all-caps style should both components be in upper case (e.g. ǈiǉan–ǇIǇAN, ǋoǌa–ǊOǊA, ǅiǆa–ǄIǄA). Unicode designates a single character for each case variant (i.e., upper case, title case and lower case) of the three digraphs.

Some English surnames such as fforbes are traditionally spelt with a digraph instead of a capital letter (at least for ff).

In the Hawaiian orthography, the ʻokina is a phonemic symbol that visually resembles a left single quotation mark. Representing the glottal stop, the ʻokina can be characterised as either a letter or a diacritic. As a unicase letter, the ʻokina is unaffected by capitalisation; it is the following letter that is capitalised instead. According to the Unicode standard, the ʻokina is formally encoded as U+02BB ʻ MODIFIER LETTER TURNED COMMA, but it is not uncommon to substitute this with a similar punctuation character, such as the left single quotation mark or an apostrophe.

### Related features

Similar orthographic and graphostylistic conventions are used for emphasis or following language-specific or other rules, including:

Font effects such as italic type or oblique type, boldface, and choice of serif vs. sans-serif.

In mathematical notation lower-case and upper-case letters have generally different meanings, and other meanings can be implied by the use of other typefaces, such as boldface, fraktur, script typeface, and blackboard bold.

Some letters of the Arabic and Hebrew alphabets and some jamo of the Korean hangul have different forms depending on placement within a word, but these rules are strict and the different forms cannot be used for emphasis.

In the Arabic and Arabic-based alphabets, letters in a word are connected, except for several that cannot connect to the following letter. Letters may have distinct forms depending on whether they are initial (connected only to the following letter), medial (connected to both neighboring letters), final (connected only to the preceding letter), or isolated (connected to neither a preceding nor a following letter).

In the Hebrew alphabet, five letters have a distinct form (see Final form) that is used when they are word-final.

In Georgian, some authors use isolated letters from the ancient Asomtavruli alphabet within a text otherwise written in the modern Mkhedruli in a fashion that is reminiscent of the usage of upper-case letters in the Latin, Greek, and Cyrillic alphabets.

In the Japanese writing system, an author has the option of switching between kanji, hiragana, katakana, and rōmaji. In particular, every hiragana character has an equivalent katakana character, and vice versa. Romanised Japanese sometimes uses lowercase letters to represent words that would be written in hiragana, and uppercase letters to represent words that would be written in katakana. Some kana characters are written in smaller type when they modify or combine with the preceding sign (yōon) or the following sign (sokuon).