Bracket
[ ]  

Brackets




A bracket is a tall punctuation mark typically used in matched pairs within text, to set apart or interject other text. Used unqualified, brackets refer to different types of brackets in different parts of the world and in different contexts.
Brackets include round brackets/parentheses, square brackets, curly brackets, angle brackets, and various other pairs of symbols.
In addition to referring to the class of all types of brackets, the unqualified word bracket is most commonly used to refer to a specific type of bracket. In modern American usage this is usually the square bracket and in modern British usage this is usually the parenthesis.
Contents
History
Chevrons (< >) were the earliest type of bracket to appear in written English. Desiderius Erasmus coined the term lunula to refer to the rounded parentheses (), recalling the shape of the crescent moon.^{[1]}
Names for various bracket symbols
Some of the following names are regional or contextual.
 ( ) — parentheses, brackets (UK, Canada, New Zealand, and Australia), parens, round brackets, soft brackets, or circle brackets
 [ ] — square brackets, closed brackets, hard brackets, crotchets,^{[2]} or brackets (US)
 { } — braces are "two connecting marks used in printing"; and in music "to connect staves to be performed at the same time" ^{[3]}(UK and US), flower brackets (India), French brackets, curly brackets, definite brackets, swirly brackets, curly braces, birdie brackets, Scottish brackets, squirrelly brackets, gullwings, seagulls, squiggly brackets, twirly brackets, Tuborg brackets (DK), accolades (NL), pointy brackets, or fancy brackets
 ⟨ ⟩ — pointy brackets, angle brackets, triangular brackets, diamond brackets, tuples, or chevrons
 < > — inequality signs, pointy brackets, or brackets. Sometimes referred to as angle brackets, in such cases as HTML markup. Occasionally known as broken brackets or brokets.^{[4]}
 ⸤ ⸥; ｢ ｣ — corner brackets
 ⟦ ⟧ — double square brackets, white square brackets
Typography
The characters ‹ › and « », known as guillemets or angular quote brackets, are actually quotation mark glyphs used in several European languages.^{[5]} Which one of each pair is the opening quote mark and which is the closing quote varies between languages.
In English, typographers generally prefer to not set brackets in italics, even when the enclosed text is italic.^{[6]} However, in other language like German, if brackets enclose text in italics, they are usually set in italics too.^{[7]}
Types and uses
Parentheses
Parentheses /pəˈrɛnθᵻsiːz/ (singular, parenthesis /pəˈrɛnθᵻsᵻs/) (also called simply brackets, or round brackets, curved brackets, oval brackets, or, colloquially, parens /pəˈrɛnz/) contain material that serves to clarify, or is aside from the main point.^{[8]} A milder effect may be obtained by using a pair of commas as the delimiter, though if the sentence contains commas for other purposes, visual confusion may result.
In American usage, parentheses are usually considered separate from other brackets, and calling them "brackets" is unusual.
Parentheses may be used in formal writing to add supplementary information, such as "Sen. John McCain (RArizona) spoke at length". They can also indicate shorthand for "either singular or plural" for nouns, e. g. "the claim(s)". It can also be used for gender neutral language, especially in languages with grammatical gender, e. g. "(s)he agreed with his (her) physician", .^{[9]}
Parenthetical phrases have been used extensively in informal writing and stream of consciousness literature. Examples include the southern American author William Faulkner (see Absalom, Absalom! and the Quentin section of The Sound and the Fury) as well as poet E. E. Cummings.
Parentheses have historically been used where the dash is currently used—that is, in order to depict alternatives, such as "parenthesis)(parentheses". Examples of this usage can be seen in editions of Fowler's.
Parentheses may be nested (generally with one set (such as this) inside another set). This is not commonly used in formal writing (though sometimes other brackets [especially square brackets] will be used for one or more inner set of parentheses, [in other words, secondary {or even tertiary} phrases can be found within the main parenthetical sentence]).^{[10]}
Any punctuation inside parentheses or other brackets is independent of the rest of the text: "Mrs. Pennyfarthing (What? Yes, that was her name!) was my landlady." In this usage, the explanatory text in the parentheses is a parenthesis. (Parenthesized text is usually short and within a single sentence. Where several sentences of supplemental material are used in parentheses the final full stop would be within the parentheses, or simply omitted. Again, the parenthesis implies that the meaning and flow of the text is supplemental to the rest of the text and the whole would be unchanged were the parenthesized sentences removed.)
Parentheses are included in the syntaxes of many computer programming languages. Typically needed to denote an argument; to tell the compiler what data type the Method/Function needs to look for first in order to initialise. In some cases, such as in LISP, parentheses are a fundamental construct of the language.
Parentheses in mathematics signify a different precedence of operators. For example: 2 + 3 × 4 equals 14, since the multiplication is done before the addition. However, (2 + 3) × 4 equals 20, because the parentheses override normal precedence, causing the addition to be done first. Some authors follow the convention in mathematical equations that, when parentheses have one level of nesting, the inner pair are parentheses and the outer pair are square brackets. Example:
A related convention is that when parentheses have two levels of nesting, curly brackets (braces) are the outermost pair. Following this convention, when more than three levels of nesting are needed, often a cycle of parentheses, square brackets, and curly brackets will continue. This helps to distinguish between one such level and the next.^{[11]}
Parentheses are also used to set apart the arguments in mathematical functions. For example, f(x) is the function f applied to the variable x. In coordinate systems parentheses are used to denote a set of coordinates; so in the Cartesian coordinate system (4, 7) may represent the point located at 4 on the xaxis and 7 on the yaxis. Parentheses may also represent intervals; (0, 5), for example, is the interval between 0 and 5, not including 0 or 5.
Parentheses may also be used to represent a binomial coefficient, and in chemistry to denote a polyatomic ion.
In Chinese and Japanese, 【 】, a combination of brackets and parentheses called 方頭括號 and sumitsuki, are used for inference in Chinese and used in titles and headings in Japanese.
 Unpaired parenthesis
Lowercase latin letters used as indexes, rather than bullets or numbers, followed by unpaired parenthesis, are used in ordered lists especially in:
 a) educational testing,
 b) technical writing and diagrams,
 c) market research, and
 d) elections
In more formal usage, "parenthesis" may refer to the entire bracketed text, not just to the punctuation marks used (so all the text in this set of round brackets may be said to be "a parenthesis", "a parenthetical", or "a parenthetical phrase").^{[12]}
Square brackets
Usage in Journalism News Media
Square brackets—also called crotchets or simply brackets (US)—are mainly used to insert explanatory material or to mark where a passage was omitted from an original material by someone other than the original author, or to mark modifications in quotations.^{[13]}
A bracketed ellipsis […] is often used to indicate omitted material: "I'd like to thank [several unimportant people] for their tolerance..."^{[14]} Bracketed comments inserted into a quote indicate when the original has been modified for clarity: "I appreciate it [the honor], but I must refuse", and "the future of psionics [see definition] is in doubt". Or one can quote the original statement "I hate to do laundry" with a modification inserted in the middle of it: He "hate[s] to do laundry".
Additionally, a small letter can be replaced by a capital one, when the beginning of the original text is omitted for succinctness, for example, when referring to a verbose original: "To the extent that policymakers and elite opinion in general have made use of economic analysis at all, they have, as the saying goes, done so the way a drunkard uses a lamppost: for support, not illumination", it can be quoted succinctly as: "[P]olicymakers (...) made use of economic analysis (...) the way a drunkard uses a lamppost: for support, not illumination." When nested parentheses are needed, brackets are used as a substitute for the inner pair of parentheses within the outer pair.^{[15]} When deeper levels of nesting are needed, convention is to alternate between parentheses and brackets at each level.
Alternatively, empty square brackets can also indicate omitted material, usually single letter only. The original "Reading is also a process and it also changes you." can be rewritten in a quote as: It has been suggested that reading can "also change[] you".
The bracketed expression "[sic]" is used after a quote or reprinted text to indicate the passage appears exactly as in the original source, where it may otherwise appear that a mistake has been made in reproduction.
In translated works, brackets are used to signify the same word or phrase in the original language to avoid ambiguity.^{[16]} For example: He is trained in the way of the open hand [karate].
Usage in Proofreading
Brackets (called moveleft symbols or move right symbols) are added to the sides of text in proofreading to indicate changes in indentation:
Move left  [To Fate I sue, of other means bereft, the only refuge for the wretched left. 

Center  ]Paradise Lost[ 
Move up 
Usage in Scientific Fields
Brackets are used in mathematics in a variety of notations, including standard notations for intervals, commutators, the floor function, the Lie bracket, the Iverson bracket, and matrices.
Brackets can also be used in chemistry to represent the concentration of a chemical substance or to denote distributed charge in a complex ion.
Brackets are used in many computer programming languages, especially those derived or inspired by the C language, to indicate array indexing operators. In this context, the opening bracket is often pronounced as "sub", indicating a subscript.
Other Uses
In linguistics, phonetic transcriptions are generally enclosed within brackets,^{[17]} often using the International Phonetic Alphabet, whereas phonemic transcriptions typically use paired slashes. Pipes ( ) are often used to indicate a morphophonemic rather than phonemic representation. Other conventions are double slashes (// //), double pipes ( ) and curly brackets ({ }). In lexicography, square brackets usually surround the section of a dictionary entry which contains the etymology of the word the entry defines.
Brackets are used to denote parts of the text that need to be checked when preparing drafts prior to finalizing a document. They often denote points that have not yet been agreed to in legal drafts and the year in which a report was made for certain case law decisions.
Curly brackets
Curly brackets—also called braces or (colloquially) squiggly brackets in the US—are used in specialized ways in poetry and music (to mark repeats or joined lines). The musical terms for this mark joining staves are accolade and "brace", and connect two or more lines of music that are played simultaneously.^{[18]} In mathematics they delimit sets, and in writing, they may be used similarly, "Select your animal {goat, sheep, cow, horse} and follow me". In many programming languages, they enclose groups of statements. Such languages (C being one of the bestknown examples) are therefore called curly bracket languages.^{[19]}
Presumably, due to the similarity of the words brace and bracket (although they do not share an etymology), many people mistakenly^{[citation needed]}treat brace as a synonym for bracket. Therefore, when it is necessary to avoid any possibility of confusion, such as in computer programming, it may be best to use the term curly bracket rather than brace. However, general usage in North American English favours the latter form.^{[citation needed]} Indian programmers often use the name "flower bracket".^{[20]}
In classical mechanics, curly brackets are often also used to denote the Poisson bracket between two quantities.
Angle brackets
Chevrons ⟨ ⟩ are often used to enclose highlighted material.
In physical sciences, chevrons are used to denote an average over time or over another continuous parameter. For example,
The inner product of two vectors is commonly written as , but the notation (a, b) is also used.
In mathematical physics, especially quantum mechanics, it is common to write the inner product between elements as , as a short version of , or , where is an operator. This is known as Dirac notation or braket notation.
In set theory, chevrons or parentheses are used to denote ordered pairs and other tuples, whereas curly brackets are used for unordered sets.
In linguistics, chevrons indicate graphemes (i.e., written letters) or orthography, as in "The English word /kæt/ is spelled ⟨cat⟩."^{[21]}^{[22]}^{[23]}
In epigraphy, they may be used for mechanical transliterations of a text into the Latin script.^{[22]}
In textual criticism, and hence in many editions of premodern works, chevrons denote sections of the text which are illegible or otherwise lost; the editor will often insert his own reconstruction where possible within them.^{[23]}
Chevrons are infrequently used to denote words that are thought instead of spoken, such as:
 ⟨ What an unusual flower! ⟩
The mathematical or logical symbols for greaterthan (>) and lessthan (<) are inequality symbols, and are not punctuation marks when so used. Nevertheless, true chevrons are not available on a typical computer keyboard, but the lessthan and greaterthan symbols are, so they are often substituted. They are loosely referred to as angled brackets or chevrons in this case.^{[citation needed]}
Single and double pairs of comparison operators (<<, >>) (meaning much smaller than and much greater than) are sometimes used instead of guillemets («, ») (used as quotation marks in many languages) when the proper characters are not available.
In comic books, chevrons are often used to mark dialogue that has been translated notionally from another language; in other words, if a character is speaking another language, instead of writing in the other language and providing a translation, one writes the translated text within chevrons. Of course, since no foreign language is actually written, this is only notionally translated.^{[24]}
Chevronlike symbols are part of standard Chinese, and Korean punctuation, where they generally enclose the titles of books: ︿ and ﹀ or ︽ and ︾ for traditional vertical printing, and 〈 and 〉 or 《 and 》 for horizontal printing. See also nonEnglish usage of quotation marks.
In continuum mechanics, chevrons may be used as Macaulay brackets.
In East Asian punctuation, angle brackets are used as quotation marks.
Floor and ceiling corners
The floor corner brackets ⌊ and ⌋, the ceiling corner brackets ⌈ and ⌉ are used to denote the integer floor and ceiling functions.
Quine corners and half brackets
The Quine corners ⌜ and ⌝ have at least two uses in mathematical logic: either as quasiquotation, a generalization of quotation marks, or to denote the Gödel number of the enclosed expression.
Half brackets are used in English to mark added text, such as in translations: "Bill saw ⸤her⸥".
In editions of papyrological texts, half brackets, ⸤ and ⸥ or ⸢ and ⸣, enclose text which is lacking in the papyrus due to damage, but can be restored by virtue of another source, such as an ancient quotation of the text transmitted by the papyrus.^{[25]} For example, Callimachus Iambus 1.2 reads: ἐκ τῶν ὅκου βοῦν κολλύ⸤βου π⸥ιπρήσκουσιν. A hole in the papyrus has obliterated βου π, but these letters are supplied by an ancient commentary on the poem. Second intermittent sources can be between ⸢ and ⸣. Quine corners are sometimes used instead of half brackets.^{[26]}
Double brackets
Double brackets (or white square brackets), ⟦ ⟧, are used to indicate the semantic evaluation function in formal semantics for natural language and denotational semantics for programming languages.^{[27]}^{[28]} The brackets stand for a function that maps a linguistic expression to its “denotation” or semantic value.
Brackets with quills
Known as "mouse parentheses" (Swedish: piggparenteser) ⁅ and ⁆ are used in Swedish dictionaries.^{[29]}
Specific uses
Computing
The various bracket characters are frequently used in many computer languages as operators or for other syntax markup. For instance, Clike languages, { and } are often used to delimit a code block, and the parameters of method calls are generally enclosed by ( and ).
Mathematics
In addition to the use of parentheses to specify the order of operations, both parentheses and brackets are used to denote an interval, also referred to as a halfopen range. The notation [a,c) is used to indicate an interval from a to c that is inclusive of a but exclusive of c. That is, [5, 12) would be the set of all real numbers between 5 and 12, including 5 but not 12. The numbers may come as close as they like to 12, including 11.999 and so forth (with any finite number of 9s), but 12.0 is not included. In some European countries, the notation [5, 12[ is also used for this. The endpoint adjoining the bracket is known as closed, whereas the endpoint adjoining the parenthesis is known as open. If both types of brackets are the same, the entire interval may be referred to as closed or open as appropriate. Whenever +∞ or −∞ is used as an endpoint, it is normally considered open and adjoined to a parenthesis. See Interval (mathematics) for a more complete treatment.
In quantum mechanics, chevrons are also used as part of Dirac's formalism, bra–ket notation, to note vectors from the dual spaces of the Bra ⟨A and the Ket B⟩. Mathematicians will also commonly write ⟨a, b⟩ for the inner product of two vectors. In statistical mechanics, chevrons denote ensemble or time average. Chevrons are used in group theory to write group presentations, and to denote the subgroup generated by a collection of elements. Note that obtuse angled chevrons are not always (and even not by all users) distinguished from a pair of lessthan and greaterthan signs <>, which are sometimes used as a typographic approximation of chevrons.
In group theory and ring theory, brackets denote the commutator. In group theory, the commutator [g, h] is commonly defined as g^{ −1} h^{ −1} g h . In ring theory, the commutator [a, b] is defined as a b − b a . Furthermore, in ring theory, braces denote the anticommutator where {a, b} is defined as a b + b a . The bracket is also used to denote the Lie derivative, or more generally the Lie bracket in any Lie algebra.
Various notations, like the vinculum have a similar effect to brackets in specifying order of operations, or otherwise grouping several characters together for a common purpose.
In the Z formal specification language, braces define a set and chevrons define a sequence.
Accounting
Traditionally in accounting, negative amounts are placed in parentheses.
Law
Brackets are used in some countries in the citation of law reports to identify parallel citations to nonofficial reporters. For example: Chronicle Pub. Co. v. Superior Court, (1998) 54 Cal.2d 548, [7 Cal.Rptr. 109]. In some other countries (such as England and Wales), square brackets are used to indicate that the year is part of the citation and parentheses are used to indicate the year the judgment was given. For example, National Coal Board v England [1954] AC 403, is in the 1954 volume of the Appeal Cases reports although the decision may have been given in 1953 or earlier, whereas (1954) 98 Sol Jo 176 reports a decision from 1954, in volume 98 of the Solicitor's Journal which may be published in 1955 or later.
When quoted material is in any way altered, the alterations are enclosed in brackets within the quotation. For example: Plaintiff asserts his cause is just, stating, "[m]y causes is [sic] just." Although in the original quoted sentence the word "my" was capitalized, it has been modified in the quotation and the change signalled with brackets. Similarly, where the quotation contained a grammatical error, the quoting author signalled that the error was in the original with "[sic]" (Latin for 'thus'). (California Style Manual, section 4:59 (4th ed.))
Sports
Tournament brackets, the diagrammatic representation of the series of games played during a tournament usually leading to a single winner, are so named for their resemblance to brackets or braces.
Encoding in digital media
Representations of various kinds of brackets in ASCII, Unicode, and HTML are given below.
Usage  Unicode  SGML/HTML/XML entities  Sample  

General purpose  U+0028  Left parenthesis  ( &lparen;  (parentheses)  
U+0029  Right parenthesis  ) &rparen;  
U+005B  Left square bracket  [  [sic]  
U+005D  Right square bracket  ]  
U+2045  Left square bracket with quill  ⁅  abonnera vb itr o. vb tr subscribe ⁅på to, for⁆; ~d buss hired coach, amer. chartered bus (formellt coach)  
U+2046  Right square bracket with quill  ⁆  
Technical/mathematical (common) 
U+003C  Lessthan sign  < <  <HTML>  
U+003E  Greaterthan sign  > >  
U+007B  Left curly bracket  {  {round, square, curly}  
U+007D  Right curly bracket  }  
Quotation (Western texts) 
U+00AB  Left double guillemet  «  « quote »  
U+00BB  Right double guillemet  »  
U+2039  Left single guillemet  ‹  ‹ x ›  
U+203A  Right single guillemet  ›  
Floor and ceiling functions^{[26]}  U+2308  Left ceiling  ⌈  ⌈ceiling⌉  
U+2309  Right ceiling  ⌉  
U+230A  Left floor  ⌊  ⌊floor⌋  
U+230B  Right floor  ⌋  
Quine corners^{[26]}  U+231C  Top right corner  ⌜  ⌜quasiquotation⌝ ⌜editorial notation⌝ 

U+231D  Top left corner  ⌝  
U+231E  Bottom right corner  ⌞  ⌞editorial notation⌟  
U+231F  Bottom left corner  ⌟  
Technical/mathematical (specialized)^{[26]} 
U+239B  Left parenthesis upper hook  ⎛ 


U+239C  Left parenthesis extension  ⎜  
U+239D  Left parenthesis lower hook  ⎝  
U+239E  Right parenthesis upper hook  ⎞  
U+239F  Right parenthesis extension  ⎟  
U+23A0  Right parenthesis lower hook  ⎠  
U+23A1  Left square bracket upper corner  ⎡ 


U+23A2  Left square bracket extension  ⎢  
U+23A3  Left square bracket lower corner  ⎣  
U+23A4  Right square bracket upper corner  ⎤  
U+23A5  Right square bracket extension  ⎥  
U+23A6  Right square bracket lower corner  ⎦  
U+23A7  Left curly bracket upper hook  ⎧ 


U+23A8  Left curly bracket middle piece  ⎨  
U+23A9  Left curly bracket lower hook  ⎩  
U+23AB  Right curly bracket upper hook  ⎫  
U+23AC  Right curly bracket middle piece  ⎬  
U+23AD  Right curly bracket lower hook  ⎭  
U+23AA  Curly bracket extension  ⎪  ⎪  
U+23B0  Upper left or lower right curly bracket section  ⎰  ⎰ ⎱ ⎱ ⎰ 

U+23B1  Upper right or lower left curly bracket section  ⎱  
U+23B4  Top square bracket  ⎴ 


U+23B5  Bottom square bracket  ⎵  
U+23B6  Bottom square bracket over top square bracket  ⎶ 


U+23B8  Left vertical box line  ⎸  ⎸boxed text⎹  
U+23B9  Right vertical box line  ⎹  
U+23DC  Top parenthesis  ⏜ 


U+23DD  Bottom parenthesis  ⏝  
U+23DE  Top curly bracket  ⏞ 


U+23DF  Bottom curly bracket  ⏟  
U+23E0  Top tortoise shell bracket  ⏠ 


U+23E1  Bottom tortoise shell bracket  ⏡  
Technical mathematical symbols^{[30]}^{[31]} 
U+27E6  Mathematical left white square bracket  ⟦  ⟦white square brackets⟧  
U+27E7  Mathematical right white square bracket  ⟧  
U+27E8  Mathematical left angle bracket  ⟨ ⟨^{[e 1]}  ⟨a, b⟩  
U+27E9  Mathematical right angle bracket  ⟩ ⟩^{[e 1]}  
U+27EA  Mathematical left double angle bracket  ⟪  ⟪A, B⟫  
U+27EB  Mathematical right double angle bracket  ⟫  
U+27EC  Mathematical left white tortoise shell bracket  ⟬  ⟬white tortoise shell brackets⟭  
U+27ED  Mathematical right white tortoise shell bracket  ⟭  
U+27EE  Mathematical left flattened parenthesis  ⟮  ⟮flattened parentheses⟯  
U+27EF  Mathematical right flattened parenthesis  ⟯  
U+2983  Left white curly bracket  ⦃  ⦃white curly brackets⦄  
U+2984  Right white curly bracket  ⦄  
U+2985  Left white parenthesis  ⦅  ⦅white/double parentheses⦆  
U+2986  Right white parenthesis  ⦆  
U+2987  Z notation left image bracket  ⦇  R⦇S⦈  
U+2988  Z notation right image bracket  ⦈  
U+2989  Z notation left binding bracket  ⦉  A⦉B⦊  
U+298A  Z notation right binding bracket  ⦊  
U+298B  Left square bracket with underbar  ⦋  ⦋underlined square brackets⦌  
U+298C  Right square bracket with underbar  ⦌  
U+298D  Left square bracket with tick in top corner  ⦍  ⦍ticked square brackets⦎  
U+298E  Right square bracket with tick in bottom corner  ⦎  
U+298F  Left square bracket with tick in bottom corner  ⦏  ⦏ticked square brackets⦐  
U+2990  Right square bracket with tick in top corner  ⦐  
U+2991  Left angle bracket with dot  ⦑  ⦑dotted angle brackets⦒  
U+2992  Right angle bracket with dot  ⦒  
U+2993  Left arc lessthan bracket  ⦓  ⦓inequality sign brackets⦔  
U+2994  Right arc greaterthan bracket  ⦔  
U+2995  Double left arc greaterthan bracket  ⦕  ⦕inequality sign brackets⦖  
U+2996  Double right arc lessthan bracket  ⦖  
U+2997  Left black tortoise shell bracket  ⦗  ⦗black tortoise shell brackets⦘  
U+2998  Right black tortoise shell bracket  ⦘  
Half brackets^{[32]}  U+2E22  Top left half bracket  ⸢  ⸢editorial notation⸣  
U+2E23  Top right half bracket  ⸣  
U+2E24  Bottom left half bracket  ⸤  ⸤editorial notation⸥  
U+2E25  Bottom right half bracket  ⸥  
Quotation (halfwidth EastAsian texts) 
U+2329  Left pointing angle bracket  〈 ⟨^{[e 1]}  〈deprecated〉  
U+232A  Right pointing angle bracket  〉 ⟩^{[e 1]}  
U+FF62  Halfwidth left corner bracket  ｢  ｢ｶﾀｶﾅ｣  
U+FF63  Halfwidth right corner angle bracket  ｣  
Quotation (fullwidth EastAsian texts) 
U+3008  Left angle bracket  〈  〈한〉  
U+3009  Right angle bracket  〉  
U+300A  Left double angle bracket  《  《한한》  
U+300B  Right double angle bracket  》  
U+300C  Left corner bracket  「  「白八櫨」  
U+300D  Right corner bracket  」  
U+300E  Left white corner bracket  『  『カタカナ』  
U+300F  Right white corner bracket  』  
U+3010  Left thick square bracket  【  【ひらがな】  
U+3011  Right thick square bracket  】  
General purpose (fullwidth EastAsian) 
U+FF08  Fullwidth left parenthesis  （  （Ｗｉｋｉ）  
U+FF09  Fullwidth right parenthesis  ）  
U+FF3B  Fullwidth left square bracket  ［  ［ｓｉｃ］  
U+FF3D  Fullwidth right square bracket  ］  
Technical/mathematical (fullwidth EastAsian) 
U+FF1C  Fullwidth lessthan sign  ＜  ＜ＨＴＭＬ＞  
U+FF1E  Fullwidth greaterthan sign  ＞  
U+FF5B  Fullwidth left curly bracket  ｛  ｛１、２｝  
U+FF5D  Fullwidth right curly bracket  ｝ 
 ↑ ^{1.0} ^{1.1} ^{1.2} ^{1.3} ⟨ and ⟩ were tied to the deprecated symbols U+2329 and U+232A in HTML4 and MathML2, but are being migrated to U+27E8 and U+27E9 for HTML5 and MathML3, as defined in XML Entity Definitions for Characters.
Braces (curly brackets) first became part of a character set with the 8bit code of the IBM 7030 Stretch.^{[33]}
The angle brackets or chevrons at U+27E8 and U+27E9 are for mathematical use and Western languages, whereas U+3008 and U+3009 are for East Asian languages. The chevrons at U+2329 and U+232A are deprecated in favour of the U+3008 and U+3009 East Asian angle brackets. Unicode discourages their use for mathematics and in Western texts,^{[26]} because they are canonically equivalent to the CJK code points U+300x and thus likely to render as doublewidth symbols. The lessthan and greaterthan symbols are often used as replacements for chevrons.
See also
 International variation in quotation marks
 Emoticon
 Japanese typographic symbols
 Order of operations
References
 ↑ Truss, Lynne. Eats, Shoots & Leaves, 2003. p. 161. ISBN 1592400876.
 ↑ Smith, John. The printer’s grammar: containing a concise history of the origin of printing; Also, an examination of the superficies, gradation, and properties of The different sizes of types cast by letter founders; Various Tables of Calculation; Models of Letter Cases; Schemes for casting off Copy and Imposing; and many other Requisites for attaining a perfect Knowledge both in the Theory and Practice of the Art of Printing. With directions to authors, compilers, &c. How to Prepare Copy, and to Correct their own Proofs. Chiefly collected from SMITH’s edition. To which are added directions for pressmen, &c. The whole calculated for the Service of All who have any Concern in the Letter Press. p. 84.
 ↑ Concise Oxford Dictionary, 10th Edition, Oxford University Press, Great Clarendon Street, Oxford OX2 2DP, UK
 ↑ "broket". Catb.org. Retrieved 20130213.
 ↑ MerriamWebster's Manual for Writers and Editors. MerriamWebster. 1998. p. 149. ISBN 087779622X. At Google Books.
 ↑ Robert Bringhurst, The Elements of Typographic Style, §5.3.2.
 ↑ Forsmann, Friedrich; DeJong, Ralf (2004). Detailtypografie [Detail Typography] (in German). Mainz: Herrmann Schmidt. p. 263. ISBN 9783874396424.
 ↑ Straus, Jane. "Parentheses — Punctuation Rules". The Blue Book of Grammar and Punctuation. grammarbook.com. Retrieved 18 April 2014.
 ↑ Slash (punctuation)#Genderneutrality in Spanish and Portuguese
 ↑ Fogarty, Mignon. "Parentheses, Brackets, and Braces". Quick and Dirty Tips. Retrieved 27 March 2011.
 ↑ http://math.about.com/od/mathhelpandtutorials/fl/ParenthesisBracesandBrackets.html
 ↑ "The Free Online Dictionary". Thefreedictionary.com. Retrieved 20130213.
 ↑ The Chicago Manual of Style, 15th ed., The University of Chicago Press, 2003, §6.104
 ↑ "Bartleby.com: Great Books Online  Quotes, Poems, Novels, Classics and hundreds more". bartleby.com.
 ↑ The Chicago Manual of Style, 15th ed., The University of Chicago Press, 2003, §6.102 and §6.106
 ↑ The Chicago Manual of Style, 15th ed., The University of Chicago Press, 2003, §6.105
 ↑ The Chicago Manual of Style, 15th ed., The University of Chicago Press, 2003, §6.107
 ↑ Decodeunicode.org > U+007B LEFT CURLY BRACKET Retrieved on May 3, 2009
 ↑ "Brace and Indent Styles and Code Convention". riedquat.de.
 ↑ K R Venugopa, Rajkumar Buyya, T Ravishankar. Mastering C++, 1999. p. 34. ISBN 0074634542.
 ↑ Bauer, Laurie (2007). "Notational conventions. Brackets". The Linguistics Student's Handbook. Edinburgh: Edinburgh University Press. p. 99.
 ↑ ^{22.0} ^{22.1} Sampson, Geoffrey (2016). "Writing systems: methods for recording language". In Allan, Keith. The Routledge Handbook of Linguistics. Routledge. p. 60.
 ↑ ^{23.0} ^{23.1} Trask, Robert Lawrence (2000). "Angle brackets". The Dictionary of Historical and Comparative Linguistics. Edinburgh: Edinburgh University Press. p. 22.
 ↑ "The Two Kinds Archive". 29 September 2004. Retrieved 20090927.
 ↑ M.L. West (1973) Textual Criticism and Editorial Technique (Stuttgart) 81.
 ↑ ^{26.0} ^{26.1} ^{26.2} ^{26.3} ^{26.4} "Miscellaneous Technical" (PDF), The Unicode Standard, Version 6.3, 2013, retrieved 20121102
 ↑ Dowty, D., Wall, R. and Peters, S.: 1981, Introduction to Montague semantics, Springer.
 ↑ Scott, D. and Strachey, C.: 1971, Toward a mathematical semantics for computer languages, Oxford University Computing Laboratory, Programming Research Group.
 ↑ See sv:Parentes
 ↑ "Miscellaneous Mathematical SymbolsA" (PDF), The Unicode Standard, Version 6.3, 2013, retrieved 20131102
 ↑ "Miscellaneous Mathematical SymbolsB" (PDF), The Unicode Standard, Version 6.3, 2013, retrieved 20131102
 ↑ "Supplemental Punctuation" (PDF), The Unicode Standard, Version 6.3, 2013, retrieved 20131102
 ↑ Bob, Bemer. "The Great Curly Brace Trace Chase". Retrieved 20090905.
Bibliography
 Lennard, John (1991). But I Digress: The Exploitation of Parentheses in English Printed Verse. Oxford: Clarendon Press. ISBN 0198112475.
 Turnbull; et al. (1964). The Graphics of Communication. New York: Holt. States that what are depicted as brackets above are called braces and braces are called brackets. This was the terminology in US printing prior to computers.