An interpunct ( · ) —also called an interpoint[1]—is a small dot used for interword separation in ancient Latin script, which also appears in some modern languages as a stand-alone sign inside a word. It is present in Unicode as code point U+00B7 · middle dot (183decimal, HTML: · ·).
The dot is vertically centered, e.g. "DONA·EIS·REQVIEM", and is therefore also called a middle dot or centered dot (Commonwealth: centred 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. The use of spaces for word separation did not appear until much later, some time between 600 and 800 AD.
The dot operator (also called middle dot and visually similar or identical to the interpunct) is a multiplication sign (instead of the × used in English-speaking countries): “a multiplied by b” is written either explicitly as a·b or implicitly as ab, depending on context.
Contents |
In British typography, an interpunct · is sometimes called a space dot. Dictionaries often use the interpunct or hyphenation point to indicate syllabification.
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.
In British English, it is often used as the decimal point, e.g. 3·14 as opposed to the American 3.14, but this usage is less common in typography than in handwritten text, as a full stop (period) is easier to type.
In the Shavian alphabet of English, the middle dot is used before a word to denote it as a proper noun.
In Catalan, the punt volat (literally, "flown dot") is used between two ⟨l⟩ (thus: ⟨l·l⟩) in cases where each belongs to a separate syllable (e.g. cel·la, 'cell'). This is to distinguish the true "double-l" pronunciation [ɫː] from that of the letter-combination ⟨ll⟩ (without a dot) which in Catalan stands for [ʎ] (e.g. cella, 'eyebrow').
In orthographic descriptions, ⟨l·l⟩ is called ela geminada ("geminate l") and ⟨ll⟩ doble ela. A period or a hyphen is frequently used when a middle dot is unavailable: col.lecció or col-lecció. This is nonetheless considered a misspelling. 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.[2] The preferred Unicode representation is ⟨l·⟩ (U+006C + U+00B7). The use of the ⟨•⟩ bullet (U+2022, •) is strongly discouraged on aesthetic grounds.
In Medieval Catalan the symbol ⟨·⟩ was sometimes used to note certain elisions, much like the modern apostrophe (see Occitan below).
There is no separate keyboard layout for Catalan; punt volat can be typed using Shift-3 in the Spanish (Spain) layout.
The Chinese language sometimes uses the interpunct (called the partition sign) 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 (Wēilián·Shāshìbǐyǎ)[3] 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.
Swedish sinologist Bernhard Karlgren used a middle dot to represent the glottal stop in his reconstruction of medieval Chinese.
See also proper name mark.
In Pe̍h-ōe-jī for Taiwanese Hokkien, 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 (see o͘). 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.
In Franco-Provençal (or Arpitan), the interpunct is used in order to distinguish the following graphemes:
The Greek ánō stigmē or ánō teleía (άνω στιγμή/άνω τελεία, lit. "upper dot") is a punctuation mark equivalent to the semicolon and is often incorrectly expressed as a middle dot; Unicode provides a unique code point: U+0387 · greek ano teleia.[4][5]
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). Dictionaries and 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 (however, the mixing of katakana, kanji, and hiragana gives some indication of word boundary).
In Japanese typography, there exist two Unicode code points:
The interpunct also has a number of other uses in Japanese, including the following: to separate titles, names and positions: 課長補佐・鈴木 (Assistant Section Head Suzuki); as a decimal point when writing numbers in kanji: 三・一四一五九二 (3.141 592); and in place of hyphens, dashes and colons when writing vertically.
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.
The dot called interpunct was used regularly in early Latin to separate words, but has long been replaced by space.
In Occitan, especially in the Gascon dialect, the interpunct (punt interior, literally, "inner dot", or ponch naut for "high/upper point") is used to distinguish the following graphemes:
Although it is considered to be a spelling error, a period is frequently used when a middle dot is unavailable: des.har, in.hèrn, which is the case for French keyboard layout.
In Old Occitan, the symbol · was sometimes used to denote certain elisions, much like the modern apostrophe, the only difference being that the word that gets to be elided is always placed after the interpunct, the word before ending either in a vowel sound or the letter n:
|
Bela Domna·l vostre cors gens |
Domna·l [ˈdonnal] = Domna, lo ("Lady, the": singular definite article) |
O pretty lady, all your grace |
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".[6] In other works, the hyphen (do-beir, -beir) or colon (do:beir, :beir) may be used for this purpose.
Runic texts use either an interpunct-like or a colon-like punctuation mark to separate words. There are two Unicode characters dedicated for this: U+16EB ᛫ runic single punctuation and U+16EC ᛬ runic multiple punctuation.
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 History Faculty Style Guide 2010[7]) and its use is still enforced by some UK-based academic journals such as The Lancet.[8]
In SI units the middle dot or NBSP is used as a multiplication sign. Only a comma or full stop (period) may be used as a decimal marker.
In mathematics, a small middle dot can be used to represent product; for example, x ∙ y for the product of x and y. When dealing with scalars, it is interchangeable with the multiplication sign: 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 full stop (period), not an interpunct.
In computing, 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) sulphate pentahydrate, CuSO4 · 5H2O.
On Mac OS X, an interpunct can be input pressing <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">⌥ Opt</kbd>+<kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">⇧ Shift</kbd>+<kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">9</kbd>. In the X Window System, it can be input by pressing <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">AltGr</kbd>+<kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">.</kbd>.
| Symbol | Character Entity | Numeric Entity | Unicode Code Point | Notes |
|---|---|---|---|---|
| · | · |
· |
U+00B7 |
interpunct, middle dot |
| · | · |
U+0387 |
Greek ánō stigmē | |
| ᛫ | ᛫ |
U+16eb |
Runic punctuation | |
| ⋅ | ⋅ |
⋅ |
U+22C5 |
dot operator (mathematics) |
| ∙ | ∙ |
U+2219 |
bullet operator (mathematics) | |
| • | • |
• |
U+2022 |
bullet, often used to mark list items |
| ‧ | ‧ |
U+2027 |
hyphenation point (dictionaries) | |
| ・ | ・ |
U+30FB |
fullwidth katakana middle dot | |
| ･ | ･ |
U+FF65 |
halfwidth katakana middle dot | |
| ּ | ּ |
U+05BC |
Hebrew point dagesh or mapiq |
Characters in the Symbol column above may not render correctly in all browsers.
For most North American Microsoft operating systems using OEM Code page 437, the Alt code is 250.