Letter case

Williamsburg eighteenth century press letters

In orthography and typography, letter case (or just case) is the distinction between majuscule (capital or upper-case) and minuscule (lower-case) letters. The term originated with the shallow drawers called type cases still used to hold the movable type for letterpress printing.

Most occidental languages (certainly those based on the Latin, Cyrillic, Greek and Armenian alphabets) use multiple letter-cases in their written form as an aid to clarity. Scripts using two separate cases are also called "bicameral scripts", while those with only one case are "unicase scripts".

In English, capital letters are used as the first letter of a sentence, a proper noun, or a proper adjective, and for initials or abbreviations. The first-person pronoun "I" and the interjection "O" are also capitalized. Lower-case letters are normally used for all other purposes. There are however situations where further capitalization may be used to give added emphasis, for example in headings and titles or to pick out certain words (often using small capitals). There are also a few pairs of words of different meanings whose only difference is capitalization of the first letter. Other languages vary in their use of capitals. For example, in German the first letter of all nouns is capitalized, while in Romance languages the names of days of the week, months of the year, and adjectives of nationality, religion, etc., begin with a lower-case letter.

If an alphabet has case, all or nearly all letters have both a majuscule and minuscule form. Both forms in each pair are considered to be the same letter: they have the same name, same pronunciation, and will be treated identically when sorting in alphabetical order. Languages have capitalization rules to determine whether majuscules or minuscules are to be used in a given context.

An example of a letter without both forms is the German ß (ess-tsett), which exists only in minuscule. When capitalized it normally becomes two letters, "SS" (although use of ß as a capital has been deemed permissible according to the recent spelling reform). This is because ß was originally a ligature of the two letters "ſs" (a long s and an s), both of which become "S" when capitalized. It later evolved into a letter in its own right. (ß is also occasionally referred to as a ligature of "sz", which recalls the way this consonant was pronounced in some medieval German dialects. The original spelling "sz" is preserved in Hungarian, which is pronounced as [s].)

Case comparison

Here is a comparison of the majuscule and minuscule versions of each letter used in the English language. The exact representation will vary according to the font used.

Upper Case:

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

Lower Case:

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

Origins of the term

Movable type on a composing stick, lying on a lower case with larger boxes for more common letters.

The terms upper case and lower case originated in the early days of the printing press used with movable type in letterpress printing. The individual type blocks used in hand typesetting are stored in shallow wooden or metal drawers, known as cases, with subdivisions into compartments known as boxes to store each individual letter. In many countries the majuscules and minuscules are stored separately, with a pair of boxes for each typeface at a specific size. For typesetting, the two cases are taken out of the storage rack and placed on a rack on the compositor's desk. By convention, the case containing the capitals (and small capitals) stands at a steeper angle at the back of the desk, with the case for the small letters, punctuation and spaces, at a shallower angle below it to the front of the desk, hence upper and lower case.

Various patterns of cases are available, often with the compartments for lower-case letters varying in size according to the frequency of use of letters, so that the commonest letters are grouped together in larger "boxes" at the centre of the case. The compositor takes the letter blocks from the compartments and places them in a composing stick, working from left to right and placing the letters upside down with the "nick" to the top, then sets the assembled type in a "galley".

The Oxford Universal Dictionary on Historical Advanced Proportional Principles (reprinted 1952) indicates that this usage of "case" (as the box or frame used by a compositor in the printing trade) was first used in 1588. Originally one large case was used for each typeface, then "divided cases", pairs of cases for upper and lower case, were introduced in Belgium by 1563, England by 1588, and France before 1723. Though pairs of cases were used in English-speaking countries and many European countries in Germany and Scandinavia the single case continued in use.

Other forms of case

The distinction between hiragana and katakana in Japanese is similar to, but not the same as, case; it may also be considered analogous to upright and italics characters. While each sound has both a hiragana and katakana, any given word will use only one of the two scripts normally. If a word is written with hiragana, it is not normally considered correct to write it with katakana, and vice versa. However, katakana may be substituted for hiragana or kanji to add emphasis or make them stand out, similar to the use of capitalization or italics in English.

Also similar to case is recent usage in Georgian, where some authors use isolated letters from the Asomtavruli alphabet within a text otherwise written in Mkhedruli in a fashion that is reminiscent of modern usage of letter case in the Latin, Greek, and Cyrillic alphabets.

Choice of case in text

A variety of styles is used in various circumstances:

• Capitalization: writing the first letter of a word in uppercase and the remaining letters in lowercase.
  • Sentence case - The most common in English prose. Only the first word is capitalized, except for proper nouns and other words which are generally capitalized by a more specific rule.
  • Title case - All words are capitalized, except for non-initial articles, short prepositions , and some other short words, e.g., The War of the Worlds.
• ALL CAPS - Only capital letters are used.
• small caps - Capital letters are used which are the size of the lower-case "x". Slightly larger small caps can be used in a Mixed Case fashion. Used for initialisms, names, mathematical entities, computer commands in printed text, and other situations where a given phrase needs to be distinguished from the main text.
• lowercase only - Sometimes used for artistic effect, such as in poetry. Also commonly seen in computer commands and SMS language, to avoid pushing the Shift key or other inconvenience.

Headings and publication titles

In English-language publications, varying conventions are used for capitalizing words in publication titles and headlines, including chapter and section headings. The rules differ substantially between individual house styles. The main examples are (from most to least capitals used):

Example								Rule
THE	VITAMINS	ARE	IN	MY	FRESH	CALIFORNIA	RAISINS	All-uppercase letters
The	Vitamins	Are	In	My	Fresh	California	Raisins	"Start case" - capitalization of all words, regardless of the part of speech
The	Vitamins	Are	in	My	Fresh	California	Raisins	Capitalization of all words, except for internal articles, prepositions, and conjunctions
The	Vitamins	are	in	My	Fresh	California	Raisins	Capitalization of all words, except for internal articles, prepositions, conjunctions, and forms of to be
The	Vitamins	are	in	my	Fresh	California	Raisins	Capitalization of all words, except for internal closed-class words
The	Vitamins	are	in	my	fresh	California	Raisins	Capitalization of all nouns
The	vitamins	are	in	my	fresh	California	raisins	Sentence case - Only the first word is capitalized, except for proper nouns and other specific rules which apply to English prose
the	vitamins	are	in	my	fresh	California	raisins	Capitalization of proper nouns only
the	vitamins	are	in	my	fresh	california	raisins	All-lowercase letters

Among U.S. publishers, it is a common typographic practice to capitalize additional words in titles. This is an old form of emphasis, similar to the more modern practice of using a larger or boldface font for titles. Most capitalize all words except for internal closed-class words, or internal articles, prepositions and conjunctions. Some capitalize longer prepositions such as "between", but not shorter ones. Some capitalize only nouns, others capitalize all words. This family of typographic conventions is known as title case. Of these various styles, only the practice of capitalizing nouns, pronouns, verbs, adverbs and adjectives but not articles, conjunctions or prepositions (though some styles except long prepositions) is considered correct in formal American English writing, according to most style guides, though others are found in less formal settings.

The convention followed by many British publishers (including scientific publishers, like Nature, magazines, like The Economist and New Scientist, and newspapers, like The Guardian and The Times) is the same used in other languages (e.g., French), namely to use sentence-style capitalization in titles and headlines, where capitalization follows the same rules that apply for sentences. This convention is sometimes called sentence case where a term is desired to clarify that title case shall not be applied. It is also widely used in the U.S., especially in bibliographic references and library catalogues. Examples of global publishers whose English-language house styles prescribe sentence-case titles and headings include the International Organization for Standardization.

In creative typography, such as music record covers and other artistic material, all styles are commonly encountered, including all-lowercase letters and mixed case (StudlyCaps).

One of the very few British style guides that do actually mention a form of title case is R.M. Ritter's "Oxford Manual of Style" (2002), which suggests capitalizing "the first word and all nouns, pronouns, adjectives, verbs and adverbs, but generally not articles, conjunctions and short prepositions".

Computers

Some sentence cases are not used in standard English, but are common in computer programming and other specialised fields:

• CamelCase (a.k.a. PascalCase) - First letter of each word capitalized, spaces and punctuation removed. This can be useful for technical situations where spaces are not allowed.
• Start Case - First letter of each word capitalized, spaces separate words. All words including short articles and prepositions start with a capital letter. For example: This Is A Start Case.
• snake_case - punctuation is removed and spaces are replaced by single underscores. Normally the letters share the same case (either UPPER_CASE_EMBEDDED_UNDERSCORE or lower_case_embedded_underscore) but the case can be mixed.
• sTuDlYcApS - Mixed case, with no semantic or syntactic significance to the use of the capitals. Sometimes only vowels are upper-case, at other times upper and lower case are alternated, but often it is just random. The name comes from the fact that it was used to imply coolness on the part of the writer, although nowadays it is more often used ironically. (It is also used to mock the violation of standard English case conventions by marketing people in the naming of computer software packages, even when there is no technical requirement to do so, e.g., Sun's naming of a windowing system NeWS.)

Case folding

The conversion of letter case in a string is common practice in computer applications, for instance to make case-insensitive comparisons. Many high-level programming languages provide simple methods for case folding, at least for the ASCII character set.

Methods

In some forms of BASIC there are two methods for case folding:

 UpperA$ = UCASE$("a")
 LowerA$ = LCASE$("A")

C and C++, as well as any C-like language that conforms to its standard library, provide these functions in the file ctype.h:

 char upperA = toupper('a');
 char lowerA = tolower('A');

Case folding is different with different character sets. In ASCII or EBCDIC, case can be folded in the following way, in C:

#define toupper(c) islower(c) ? (c) - 'a' + 'A' : (c)
#define tolower(c) isupper(c) ? (c) - 'A' + 'a' : (c)

This only works because the alphanumeric letters of upper and lower cases are spaced out equally. In ASCII they are consecutive, whereas with EBCDIC they are not, nonetheless the upper case letters are arranged in the same pattern and with the same gaps as are the lower case letters so the technique still works.

Some computer programming languages offer facilities for converting text to a form in which all words are first-letter capitalized. Visual Basic calls this "proper case"; Python calls it "title case". This differs from usual title casing conventions, such as the English convention in which minor words are not capitalized.

Unicode case folding

Unicode defines case folding through the three case-mapping properties of each character: uppercase, lowercase and titlecase. These properties relate all characters in scripts with differing cases to the other case variants of the character.

Importance of case in the identification of scripts

As briefly discussed in Unicode Technical Note #26, "In terms of implementation issues, any attempt at a unification of Latin, Greek, and Cyrillic would wreak havoc [and] make casing operations an unholy mess, in effect making all casing operations context sensitive [...]". In other words, while the shapes of letters like A, B, E, H, K, M, O, P, T, X, Y and so on are shared between the Latin, Greek, and Cyrillic alphabets (and small differences in their canonical forms may be considered to be of a merely typographical nature), it would still be problematic for a multilingual character set or a font to provide only a single codepoint for, say, uppercase letter B, as this would make it quite difficult for a wordprocessor to change that single uppercase letter to one of the three different choices for the lower case letter, b (Latin), β (Greek), or в (Cyrillic). Without letter case, a 'unified European alphabet'—such as ABБCГDΔΕZЄЗFΦGHIИJ...Z, with an appropriate subset for each language—is feasible; but considering letter case, it becomes very clear that these alphabets are rather distinct sets of symbols.

See also

• Sentence case
• Capitalization
• Unicase
• CamelCase
• StudlyCaps