pretonic

Interpunct

An interpunct (· ) is a small dot used for interword separation in ancient Latin script, being perhaps the first consistent visual representation of word boundaries in written language. The dot is vertically centered, e.g. "DONA·EIS·REQVIEM", and is therefore also called a middle dot or centered dot. In addition to the round dot form, inscriptions sometimes use a small equilateral triangle for the interpunct, pointing either up or down. Such triangles can be found on inscriptions on buildings in the twentieth century. Ancient Greek, by contrast, had not developed interpuncts; all the letters ran together. When a wave of enthusiasm for all things Greek swept ancient Rome, the use of interpuncts disappeared, presumably being inadequately fashionable. The use of spaces for word separation didn't appear until much later, some time between 600 and 800 AD.

In Unicode, the interpunct is code point U+00B7, or 0183 in decimal. The HTML entity for an interpunct is · (introduced in HTML 3.2). See also "Similar symbols", below.

In written language

English

In British typography, an interpunct · is sometimes called a space dot.

In some word processors, interpuncts are used to denote either hard space or space characters. In others, it is used to indicate a space when put in paragraph format to show indentations and spaces.

It is also used as a decimal point, e.g. 7·85, although this usage has declined in recent decades.

Shavian

In the Shavian alphabet of English, the middle dot is used before a word to denote it as a proper noun.

Catalan

In Catalan, the punt volat (literally, "flown dot") is used between two ls (thus: l·l) in cases where each belongs to a separate syllable (e.g. col·lecció, 'collection'). This is to distinguish the true "double-l" pronunciation from that of the letter-combination ll (without a dot) which in Catalan stands for palatal lateral IPA: /ʎ/ (lloc "place", castellà "Castilian", castell "castle"). In orthographic descriptions, l·l is called ela geminada ("geminate l") and ll doble ela. Although considered as a spelling mistake, a period or a hyphen is frequently used when a middle dot is unavailable: col.lecció or col-lecció. Unicode has unique code points for the letters Ŀ (U+013F) and ŀ (U+0140), but they are compatibility characters and are not frequently used nor recommended. The preferred Unicode representation is l· (U+006C + U+00B7). The use of • bullet (U+2022, •) is considered inaesthetic.

In Medieval Catalan the symbol '·' was sometimes used to note certain elisions, much like the modern apostrophe.

There is no separate keyboard layout for Catalan; punt volat can be typed using Shift-3 in the Spanish (Spain) layout.

Chinese

The Chinese language sometimes uses the interpunct (called the partition sign) to separate words; since Chinese script has no word spacing, the interpunct is used in cases which might otherwise be ambiguous. The partition sign is more frequently used to separate the given name and the family name of non-Chinese, or unsinicized or desinicized minority ethnic groups in China, for example, 威廉·莎士比亚 (Weilian·Shashibiya) is the transliteration of "William Shakespeare", and the partition sign is inserted in between the characters signifying the sound of "William" and those for "Shakespeare". The Chinese partition sign is also used to separate book title and chapter title when they are mentioned consecutively (with book title first, then chapter).

In Chinese, the middle dot is also fullwidth in printed matter, but the regular middle dot (·) is used in computer input, which is then rendered as fullwidth in Chinese-language fonts. Note that while some fonts may render the Japanese katakana middle dot as a square under great magnification, this is not a defining property of the middle dot that is used in China or Japan.

Bernhard Karlgren used a middle dot to represent the glottal stop in his reconstruction of medieval Chinese.

Taiwanese

In Taiwanese pe̍h-ōe-jī, middle dot is often used as a workaround for dot above right diacritic because most early encoding systems did not support this diacritic. This is now encoded as U+0358 COMBINING DOT ABOVE RIGHT. Unicode did not support this diacritic until June 2004. Newer fonts often support it natively; however, the practice of using middle dot still exists. Historically, it was derived in the late 19th century from an older barred-o with curly tail as an adaptation to the typewriter.

Franco-Provençal

In Franco-Provençal (or Arpitan), the interpunct is used in order to distinguish the following graphemes:

ch· (pronounced /ʃ/) versus ch (pronounced /ts/).
j· (pronounced /ʒ/) versus j (pronounced /dz/).
g· before e, i (pronounced /ʒ/) versus g before e, i (pronounced /dz/).

Georgian language

The Georgian language uses · (middot) as a comma.

Greek

The Greek (άνω τελεία, a semicolon-like punctuation mark, lit. "upper dot") is often expressed as a middle dot. Although Unicode provides a unique code point for it (U+0387), U+00B7 is preferred.

Japanese

Interpuncts are often used to separate transcribed foreign words written in Katakana. For example, "Can't Buy Me Love" becomes 「キャント・バイ・ミー・ラヴ」 (Kyanto·bai·mī·ravu). A middle dot is also sometimes used to separate lists in Japanese instead of the Japanese comma ("、" known as tōten). Grammar lessons in Japanese sometimes also use a similar symbol to separate a verb suffix from its root.

However, the Japanese writing system usually does not use space or punctuations to separate words; instead, the mixture of katakana, kanji, and hiragana gives some indication of word boundary.

In Japanese typography, the "katakana middle dot" (as the Unicode consortium calls it) has a fixed width that is the same as most kana characters, known as fullwidth.

Korean

Interpuncts are used in written Korean to denote a list of two or more words, more or less in the same way a slash(/) is used to juxtapose words in many other languages. The use of interpuncts has declined in years of digital typography and especially in place of slashes, but in the strictest sense, a slash cannot replace a middle dot in Korean typography.

Latin

The dot called interpunct was used regularly in early Latin, but has long been replaced by space.

Occitan

In Occitan, especially in the Gascon dialect, the interpunct (punt interior, literally, "inner dot"), is used in order to distinguish the following graphemes:

s·h (pronounced /s/ + /h/) versus sh (pronounced /ʃ/), for example: des·har ('to undo') / deishar ('to leave').
n·h (pronounced /n/ + /h/) versus nh (pronounced /ɲ/), for example: in·hèrn ('hell') / vinha ('vineyard').

Although it is considered to be a spelling mistake, a period is frequently used when a middle dot is unavailable: des.har, in.hèrn. The use of • bullet (•) is considered unaesthetic.

In Medieval Occitan the symbol '·' was sometimes used to note certain elisions, much like the modern apostrophe.

Old Irish

In many linguistic works discussing Old Irish (but not in actual Old Irish manuscripts), the interpunct is used to separate a pretonic preverbal element from the stressed syllable of the verb, e.g. do·beir "says". It is also used in citing the verb forms used after such preverbal elements, e.g. ·beir "carries", to distinguish them from forms used without preverbs, e.g. beirid "carries". In other works, the hyphen (do-beir, -beir) or colon (do:beir, :beir) may be used for this purpose.

Runes

Runic texts use a semicolon-like punctuation mark to separate words.

In mathematics and science

In British publications up to the mid-1970s, especially scientific and mathematical texts, the decimal point was commonly typeset as a middle dot. When the British currency was decimalised in 1971, the official advice issued was to write decimal amounts with a raised point (thus: £21·48) and to use a decimal point "on the line" only when typesetting constraints made it unavoidable. The widespread introduction of electronic typewriters and calculators soon afterwards was probably a major factor contributing to the decline of the raised decimal point, although it can still sometimes be encountered in academic circles (e.g., Cambridge University 2006) and is fairly commonly used by mathematics teachers in schools.

In mathematics, a small middle dot can be used to represent the product; for example, x ∙ y for the product of x and y. When dealing with scalars, it is interchangeable with the times symbol: x ⋅ y means the same thing as x × y, but × is easily confused with the letter x. However, when dealing with vectors, the dot product is distinct from the cross product. This usage has its own designated code point in Unicode, U+2219 (∙), called the "bullet operator". It is also sometimes used to denote the "AND" relationship in formal logic, due to the relationship between these two operations. In situations where the interpunct is used as a decimal point (as noted above, by many mathematics teachers in some countries), then the multiplication sign used is usually a period, not an interpunct.

In computers, the middle dot is usually used to indicate white space in various software applications such as word processing, graphic design, web layout, desktop publishing, or software development programs. It allows the user to see where white space is located in the document, and what sizes of white space are used, since normally white space is invisible so tabs, spaces, non-breaking spaces, and such are indistinguishable from one another.

In chemistry, the middle dot is used to separate the parts of formulas of addition compounds, mixture salts or solvates (mostly hydrates), such as of copper(II) sulfate pentahydrate, CuSO₄ · 5H₂O.

Similar symbols

Symbol	Character Entity	Numeric Entity	Unicode Code Point	Notes
·	`·`	`·`	`U+00B7`	interpunct, middle dot
·		`·`	`U+0387`	Greek ano teleia
⋅	`⋅`	`⋅`	`U+22C5`	dot operator (mathematics)
∙		`∙`	`U+2219`	bullet operator (mathematics)
•	`•`	`•`	`U+2022`	bullet, often used to mark list items
‧		`‧`	`U+2027`	hyphenation point
・		`・`	`U+30FB`	fullwidth katakana middle dot
･		`･`	`U+FF65`	halfwidth katakana middle dot
ּ		`ּ`	`U+05BC`	Hebrew point dagesh or mapiq