Letter case

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 and so on 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"), but the ß letter may be used as a capital to prevent confusion in special cases, such as names. 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 and pronounced [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.

{|align="center" |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

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.

Computers

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

CamelCase: First letter of each word is capitalized, spaces and punctuation removed. If the very first letter is capitalized, as in "CamelCase" (or "PowerPoint"), the term "upper camel case" may be used; this is also known as "Pascal case" or "Bumpy case". "Lower camel case" describes a variation, as in "camelCase" (or "iPod" or "eBay"), in which the very first letter is in lower case.

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.

Studly caps: Mixed case, as in "StUdLyCaPs", 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 marketers in the naming of computer software packages, even when there is no technical requirement to do so—e.g., Sun Microsystems' 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 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

CamelCase

Capitalization

Sentence case

StudlyCaps

Unicase

References

External links

Convert text to title case

Category:Orthography Category:Typography