This article needs additional citations for verification. (March 2022) 
Brackets  


A bracket is either of two tall fore or backfacing punctuation marks commonly used to isolate a segment of text or data from its surroundings. Typically deployed in symmetric pairs, an individual bracket may be identified as a left or right bracket or, alternatively, an opening bracket or closing bracket,^{[1]} respectively, depending on the directionality of the context.
Specific forms of the mark include rounded brackets (also called parentheses), square brackets, curly brackets (also called braces), and angle brackets (also called chevrons), as well as various less common pairs of symbols.
As well as signifying the overall class of punctuation, the word bracket is commonly used to refer to a specific form of bracket, which varies from region to region. In most Englishspeaking countries, an unqualified 'bracket' refers to the round bracket; in the United States, the square bracket.
Various forms of brackets are used in mathematics, with specific mathematical meanings, often for denoting specific mathematical functions and subformulas.
Chevrons ⟨ ⟩ were the earliest type of bracket to appear in written English. Desiderius Erasmus Roterodamus coined the term lunula to refer to the rounded parentheses ( ) recalling the shape of the crescent moon (Latin: luna).^{[2]}
Most typewriters only had parenthesis (and quotes). Square brackets appeared with some teleprinters.
Braces (curly brackets) first became part of a character set with the 8bit code of the IBM 7030 Stretch.^{[3]}
In 1961, ASCII contained parenthesis, square, and curly brackets, and also lessthan and greaterthan signs that could be used as angle brackets.
In English, typographers mostly prefer not to set brackets in italics, even when the enclosed text is italic.^{[4]} However, in other languages like German, if brackets enclose text in italics, they are usually also set in italics.^{[5]}
This section possibly contains original research. (March 2022) 
Parenthesis  


Look up parenthesis or ( ) in Wiktionary, the free dictionary. 
Parentheses /pəˈrɛnθɪsiːz/ (singular, parenthesis /pəˈrɛnθɪsɪs/) are also called "brackets" (UK, Ireland, Canada, West Indies, New Zealand, South Africa and Australia), "parens" /pəˈrɛnz/, "round brackets", "circle brackets" or "smooth brackets".
Parentheses contain adjunctive material that serves to clarify (in the manner of a gloss) or is aside from the main point.^{[6]} 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. That issue is fixed by using a pair of dashes instead, to bracket the parenthetical.
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 "Senator John McCain (R  Arizona) 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" (the slash in the second instance, as one alternative is replacing the other, not adding to it).
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 in alternatives, such as "parenthesis)(parentheses". Examples of this usage can be seen in ions 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]).
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 use, 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.
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").^{[7]}
In linguistics, parentheses are used for indistinguishable^{[8]} or unidentified utterances. They are also seen for silent articulation (mouthing),^{[9]} where the expected phonetic transcription is derived from lipreading, and with periods to indicate silent pauses, for example (…) or (2 sec).
An unpaired right parenthesis is often used as part of a label in an ordered list:^{[citation needed]}
a) educational testing,
b) technical writing and diagrams,
c) market research, and
d) elections.
Traditionally in accounting, contra amounts are placed in parentheses. A debit balance account in a series of cr balances will have parenthesis and vice versa.
Parentheses are used in mathematical notation to indicate grouping, often inducing a different order of operations. For example: in the usual order of algebraic operations, 4 × 3 + 2 equals 14, since the multiplication is done before the addition. However, 4 × (3 + 2) 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.^{[citation needed]}
Various notations, like the vinculum, have a similar effect in specifying order of operations, or otherwise grouping several characters together for a common purpose.
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 be used exclusively or in combination with square brackets to represent intervals.
Parentheses may be used to represent a binomial coefficient, and also matrices.
Parentheses are included in the syntaxes of many 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. They are also often used for scoping functions and operators and for arrays. In syntax diagrams they are used for grouping, such as in extended Backus–Naur form.
If it is desired to include the subgenus when giving the scientific name of an animal species or subspecies, the subgenus's name is provided in parentheses between the genus name and the specific epithet.^{[10]} For instance, Polyphylla (Xerasiobia) alba is a way to cite the species Polyphylla alba while also mentioning that it's in the subgenus Xerasiobia.^{[11]} There is also a convention of citing a subgenus by enclosing it in parentheses after its genus, e.g., Polyphylla (Xerasiobia) is a way to refer to the subgenus Xerasiobia within the genus Polyphylla.^{[12]} Parentheses are similarly used to cite a subgenus with the name of a prokaryotic species, although the International Code of Nomenclature of Prokaryotes (ICNP) requires the use of the abbreviation "subgen." as well, e.g., Acetobacter (subgen. Gluconoacetobacter) liquefaciens.^{[13]}
In some contexts, it is typical to cite the author's name alongside the taxon. In these contexts, parentheses mean that the author placed that species in a different genus from the one in that combination. The International Code of Zoological Nomenclature gives the example of Hymenolepis diminuta (Rudolphi, 1819) to indicate that Karl Rudolphi did not consider this species to be in the genus Hymenolepis when he first described the species. The author citation in zoology also allows the possibility of citing whoever transferred the species to the new genus, as in, Methiolopsis geniculata (Stål, 1878) Rehn, 1957.^{[14]} Parentheses are similarly used for new combinations of prokaryotes as well; the ICNP provides the example: Microbacterium oxydans (Chatelain and Second 1966) Schumann et al. 1999 to indicate that Chatelain and Second first described the species in a different genus, namely Brevibacterium, but in 1999 Schumann and colleagues transferred it to its present genus.^{[15]} Author citations in botany also use parentheses in this way where the author (or abbreviation thereof) of the basionym is in parentheses followed by the author (or abbreviation thereof) of whoever created that particular combination; the International Code of Nomenclature for algae, fungi, and plants provides the example Helianthemum aegyptiacum (L.) Mill. to indicate that Carl Linnaeus first described this species in a different genus, in this case Cistus, but then Philip Miller transferred it to the genus Helianthemum.^{[16]}
Parentheses are used in chemistry to denote a repeated substructure within a molecule, e.g. HC(CH_{3})_{3} (isobutane) or, similarly, to indicate the stoichiometry of ionic compounds with such substructures: e.g. Ca(NO_{3})_{2} (calcium nitrate).
They can be used in various fields as notation to indicate the amount of uncertainty in a numerical quantity. For example:^{[17]}
is equivalent to:
e.g. the value of the Boltzmann constant could be quoted as 1.38064852(79)×10^{−23} J⋅K^{−1} .
Square brackets  


Look up square bracket, Unsupported titles/Square brackets, Unsupported titles/Right square bracket, Unsupported titles/Left square bracket, or crotchet in Wiktionary, the free dictionary. 
Square brackets [ and ] are also called simply "brackets" (US), as well as "crotchets", "closed brackets", or "hard brackets".^{[18]}
Tournament brackets, the diagrammatic representation of the series of games played during a sports tournament usually leading to a single winner, are so named for their resemblance to brackets or braces.
Square brackets are often used to insert explanatory material or to mark where a [word or] passage was omitted from an original material by someone other than the original author, or to mark modifications in quotations.^{[19]} In transcribed interviews, sounds, responses and reactions that are not words but that can be described are set off in square brackets — "... [laughs] ...".
When quoted material is in any way altered, the alterations are enclosed in square brackets within the quotation to show that the quotation is not exactly as given, or to add an annotation.^{[20]} For example: The Plaintiff asserted his cause is just, stating,
[m]y causes is [sic] just.
In the original quoted sentence, the word "my" was capitalized: it has been modified in the quotation given and the change signalled with brackets. Similarly, where the quotation contained a grammatical error (is/are), the quoting author signalled that the error was in the original with "[sic]" (Latin for 'thus').
A bracketed ellipsis, [...], is often used to indicate omitted material: "I'd like to thank [several unimportant people] for their tolerance [...]"^{[21]} Bracketed comments inserted into a quote indicate where 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 (sometimes grammatical) modification inserted: He "hate[s] to do laundry".
Additionally, a small letter can be replaced by a capital one, when the beginning of the original printed text is being quoted in another piece of text or when the original text has been 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", can be quoted succinctly as: "[P]olicymakers [...] have made use of economic analysis [...] the way a drunkard uses a lamppost: for support, not illumination." When nested parentheses are needed, brackets are sometimes used as a substitute for the inner pair of parentheses within the outer pair.^{[22]} 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".^{[23]}
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.^{[24]} For example: He is trained in the way of the open hand [karate].
Style and usage guides originating in the news industry of the twentieth century, such as the AP Stylebook, recommend against the use of square brackets because "They cannot be transmitted over news wires."^{[25]} However, this guidance has little relevance outside of the technological constraints of the industry and era.
In linguistics, phonetic transcriptions are generally enclosed within square brackets,^{[26]} often using the International Phonetic Alphabet#Brackets and transcription delimiters, 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 (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 
Square brackets are used to denote parts of the text that need to be checked when preparing drafts prior to finalizing a document.
Square 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
This case is in the 1954 volume of the Appeal Cases reports, although the decision may have been given in 1953 or earlier. Compare with:
(1954) 98 Sol Jo 176
This citation reports a decision from 1954, in volume 98 of the Solicitors Journal which may be published in 1955 or later.
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.
Brackets are used in mathematics in a variety of notations, including standard notations for commutators, the floor function, the Lie bracket, equivalence classes, the Iverson bracket, and matrices.
Square brackets may be used exclusively or in combination with parentheses to represent intervals. [0,5] For example, represents the set of real numbers from 0 to 5 inclusive. Both parentheses and brackets are used to denote a halfopen interval; [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, but 12.0 is not included. In some European countries, the notation [5, 12[ is also used. The endpoint adjoining the square bracket is known as closed, whereas the endpoint adjoining the parenthesis is known as open.
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 .
Square brackets can also be used in chemistry to represent the concentration of a chemical substance in solution and to denote charge a Lewis structure of an ion (particularly distributed charge in a complex ion), repeating chemical units (particularly in polymers) and transition state structures, among other uses.
Brackets are used in many computer programming languages, primarily for array indexing. But they are also used to denote general tuples, sets and other structures, just as in mathematics. There may be several other uses as well, depending on the language at hand. In syntax diagrams they are used for optional portions, such as in extended Backus–Naur form.
Curly brackets  


Look up curly bracket, Unsupported titles/Curly brackets, Unsupported titles/Right curly bracket, Unsupported titles/Left curly bracket, squiggly, accolade, or brace in Wiktionary, the free dictionary. 
Curly brackets { and } are also known as "curly braces" or simply "braces"^{[27]} (UK and US), "definite brackets", "swirly brackets", "birdie brackets", "French brackets", "Scottish brackets", "squirrelly brackets", "gullwings", "seagulls", "squiggly brackets", "twirly brackets", "Tuborg brackets" (DK), "accolades" (NL), "pointy brackets", "fancy brackets", "M Braces", "moustache brackets", "squiggly parentheses", or "flower brackets" (India).
Curly brackets are rarely used in prose and have no widely accepted use in formal writing, but may be used to mark words or sentences that should be taken as a group, to avoid confusion when other types of brackets are already in use, or for a special purpose specific to the publication (such as in a dictionary). More commonly, they are used to indicate a group of lines that should be taken together, such as in when referring to several lines of poetry that should be repeated.^{[28]}^{[better source needed]}
As an extension to the International Phonetic Alphabet (IPA), braces are used for prosodic notation.
In music, they are known as "accolades" or "braces", and connect two or more lines (staves) of music that are played simultaneously.^{[29]}
In many programming languages, curly brackets enclose groups of statements and create a local scope. Such languages (C, C#, C++ and many others) are therefore called curly bracket languages.^{[30]} They are also used to define structures and enumerated type in these languages.
In syntax diagrams they are used for repetition, such as in extended Backus–Naur form.
In the Z formal specification language, braces define a set.
In mathematics they delimit sets and are often also used to denote the Poisson bracket between two quantities.
In ring theory, braces denote the anticommutator where {a, b} is defined as a b + b a .
This section needs additional citations for verification. (November 2012) 
Angle brackets  


Look up angle bracket, pointy bracket, diamond bracket, or broket in Wiktionary, the free dictionary. 
"Angle brackets" ⟨ and ⟩ are also called "chevrons", "pointy brackets", "triangular brackets", "diamond brackets", "tuples", "guillemets", "left and right carets", "broken brackets", or "brokets".^{[31]}
The ASCII lessthan and greaterthan characters <> are often used for angle brackets. In most cases only those characters are accepted by computer programs, the Unicode angle brackets are not recognized (for instance in HTML tags). The characters for "single" guillemets ‹› are also often used, and sometimes normal guillemets «» when nested angle brackets are needed.
Angle brackets are larger than lessthan and greaterthan signs, which in turn are larger than guillemets.
Angle brackets are infrequently used to denote words that are thought instead of spoken, such as:
In textual criticism, and hence in many ions of premodern works, chevrons denote sections of the text which are illegible or otherwise lost; the or will often insert their own reconstruction where possible within them.^{[32]}
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. Since no foreign language is actually written, this is only notionally translated.^{[citation needed]}
In linguistics, angle brackets identify graphemes (e.g., letters of an alphabet) or orthography, as in "The English word /kæt/ is spelled ⟨cat⟩."^{[33]}^{[34]}^{[32]}
In epigraphy, they may be used for mechanical transliterations of a text into the Latin script.^{[34]}
In East Asian punctuation, angle brackets are used as quotation marks. Chevronlike symbols are part of standard Chinese, Japanese 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.
Angle brackets (or 'chevrons') are used in group theory to write group presentations, and to denote the subgroup generated by a collection of elements. In set theory, chevrons or parentheses are used to denote ordered pairs^{[35]} and other tuples, whereas curly brackets are used for unordered sets.
In physical sciences and statistical mechanics, angle brackets are used to denote an average (expected value) over time or over another continuous parameter. For example:
In mathematical physics, especially quantum mechanics, it is common to write the inner product between elements as ⟨ab⟩, as a short version of ⟨a·b⟩, or ⟨aÔb⟩, where Ô is an operator. This is known as Dirac notation or bra–ket notation, to note vectors from the dual spaces of the Bra ⟨A and the Ket B⟩. But there are other notations used.
In continuum mechanics, chevrons may be used as Macaulay brackets.
In C++ chevrons (actually lessthan and greaterthan) are used to surround arguments to templates.
In the Z formal specification language chevrons define a sequence.
In HTML, chevrons (actually 'greater than' and 'less than' symbols) are used to bracket meta text. For example <b>
denotes that the following text should be displayed as bold. Pairs of meta text tags are required – much as brackets themselves are usually in pairs. The end of the bold text segment would be indicated by </b>
. This use is sometimes extended as an informal mechanism for communicating mood or tone in digital formats such as messaging, for example adding "<sighs>" at the end of a sentence.
Look up 【 】 in Wiktionary, the free dictionary. 
Some East Asian languages use lenticular brackets 【 】, a combination of square brackets and round brackets called 方頭括號 (fāngtóu kuòhào) in Chinese and すみ付き (sumitsuki) in Japanese. They are used in titles and headings in both Chinese^{[36]} and Japanese. In Japanese, they are most frequently seen in dictionaries for quoting Chinese characters and SinoJapanese loanwords.
Look up ⌊ ⌋ or ⌈ ⌉ in Wiktionary, the free dictionary. 
The floor corner brackets ⌊ and ⌋, the ceiling corner brackets ⌈ and ⌉ (U+2308, U+2309) are used to denote the integer floor and ceiling functions.
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 ions 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.^{[37]} 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.^{[38]}
Double brackets (or white square brackets or Scott brackets), ⟦ ⟧, are used to indicate the semantic evaluation function in formal semantics for natural language and denotational semantics for programming languages.^{[39]}^{[40]} The brackets stand for a function that maps a linguistic expression to its “denotation” or semantic value. In mathematics, double brackets may also be used to denote intervals of integers or, less often, the floor function. In papyrology, following the Leiden Conventions, they are used to enclose text that has been deleted in antiquity.^{[41]}
Known as "spike parentheses" (Swedish: piggparenteser), ⁅
and ⁆
are used in Swedish bilingual dictionaries to enclose supplemental constructions.^{[42]}
Representations of various kinds of brackets in Unicode and HTML are given below.
Uses  Unicode  SGML/HTML/XML entities  Sample  

General purpose^{[43]}  U+0028  Left parenthesis  ( &lparen;  (parentheses) 
U+0029  Right parenthesis  ) &rparen;  
U+005B  Left square bracket  [  [sic]  
U+005D  Right square bracket  ]  
Technical/mathematical (common)^{[43]} 
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)^{[44]}^{[45]} 
U+00AB  Leftpointing double angle quotation mark  «  «Spanish quote», « French quote » or »German quote« 
U+00BB  Rightpointing double angle quotation mark  »  
U+2039  Single leftpointing angle quotation mark  ‹  ‹ x ›  
U+203A  Single rightpointing angle quotation mark  ›  
U+201C  Left double quotation mark  “  “English quote”  
U+201D  Right double quotation mark  ”  
U+2018  Left single quotation mark  ‘  ‘English quote’  
U+2019  Right single quotation mark  ’  
U+201A  Single low9 quotation mark  ‚ ‚  ‚German quote‘ or ‚Polish quote’  
U+201E  Double low9 quotation mark  „ „  „German quote“ or „Polish quote”  
Floor and ceiling functions^{[38]}  U+2308  Left ceiling  ⌈  ⌈ceiling⌉ 
U+2309  Right ceiling  ⌉  
U+230A  Left floor  ⌊  ⌊floor⌋  
U+230B  Right floor  ⌋  
Quine corners^{[38]}  U+231C  Top left corner  ⌜  ⌜quasiquotation⌝ ⌜orial notation⌝ 
U+231D  Top right corner  ⌝  
U+231E  Bottom left corner  ⌞  ⌞orial notation⌟  
U+231F  Bottom right corner  ⌟  
Technical/mathematical (specialized)^{[38]}^{[46]}^{[47]}^{[48]}  
U+207D  Superscript left parenthesis  ⁽  X⁽²⁾  
U+207E  Superscript right parenthesis  ⁾  
U+208D  Subscript left parenthesis  ₍  X₍₂₎  
U+208E  Subscript right parenthesis  ₎  
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  ⏡  
U+27C5  Left sshaped bag delimiter  ⟅  ⟅...⟆  
U+27C6  Right sshaped bag delimiter  ⟆  
U+27D3  Lower right corner with dot  ⟓  ⟓pullback...pushout⟔  
U+27D4  Upper left corner with dot  ⟔  
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  ⦉  ⦉x:ℤ⦊  
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+2990  Right square bracket with tick in top corner  ⦐  
U+298E  Right square bracket with tick in bottom corner  ⦎  ⦏ticked square brackets⦎  
U+298F  Left square bracket with tick in bottom 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  ⦘  
U+29D8  Left wiggly fence  ⧘  ⧘...⧙  
U+29D9  Right wiggly fence  ⧙  
U+29DA  Left double wiggly fence  ⧚  ⧚...⧛  
U+29DB  Right double wiggly fence  ⧛  
U+29FC  Leftpointing curved angle bracket  ⧼  ⧼...⧽  
U+29FD  Rightpointing curved angle bracket  ⧽  
Half brackets^{[49]}  U+2E22  Top left half bracket  ⸢  ⸢orial notation⸣ 
U+2E23  Top right half bracket  ⸣  
U+2E24  Bottom left half bracket  ⸤  ⸤orial notation⸥  
U+2E25  Bottom right half bracket  ⸥  
Dingbats^{[50]}  U+2768  Medium left parenthesis ornament  ❨  ❨medium parenthesis ornament❩ 
U+2769  Medium right parenthesis ornament  ❩  
U+276A  Medium flattened left parenthesis ornament  ❪  ❪medium flattened parenthesis ornament❫  
U+276B  Medium flattened right parenthesis ornament  ❫  
U+276C  Medium leftpointing angle bracket ornament  ❬  ❬medium angle bracket ornament❭  
U+276D  Medium rightpointing angle bracket ornament  ❭  
U+2770  Heavy leftpointing angle bracket ornament  ❰  ❰heavy angle bracket ornament❱  
U+2771  Heavy rightpointing angle bracket ornament  ❱  
U+276E  Heavy leftpointing angle quotation mark ornament  ❮  ❮heavy angle quotation ornament❯  
U+276F  Heavy rightpointing angle quotation mark ornament  ❯  
U+2772  Light left tortoise shell bracket ornament  ❲  ❲light tortoise shell bracket ornament❳  
U+2773  Light right tortoise shell bracket ornament  ❳  
U+2774  Medium left curly bracket ornament  ❴  ❴medium curly bracket ornament❵  
U+2775  Medium right curly bracket ornament  ❵  
Arabic (Quranic quotations)^{[51]}  U+FD3E  Ornate left parenthesis  ﴾  ﴿قُلْ صَدَقَ ٱللَّهُ﴾ 
U+FD3F  Ornate right parenthesis  ﴿  
N'Ko^{[49]}  U+2E1C  Left low paraphrase bracket  ⸜  ⸜ߒߞߏ⸝ 
U+2E1D  Right low paraphrase bracket  ⸝  
Ogham^{[52]}  U+169B  Ogham feather mark  ᚛  ᚛ᚑᚌᚐᚋ᚜ 
U+169C  Ogham reversed feather mark  ᚜  
Old Hungarian  U+2E42  Double lowreversed9 quotation mark  ⹂  ⹂ 
Tibetan^{[53]}  U+0F3A  Tibetan mark gug rtags gyon  ༺  ༺དབུ་ཅན་༻ 
U+0F3B  Tibetan mark gug rtags gyas  ༻  
U+0F3C  Tibetan mark ang khang gyon  ༼  ༼༡༢༣༽  
U+0F3D  Tibetan mark ang khang gyas  ༽  
New Testament orial marks^{[49]}  U+2E02  Left substitution bracket  ⸂  ⸂...⸃ 
U+2E03  Right substitution bracket  ⸃  
U+2E04  Left dotted substitution bracket  ⸄  ⸄...⸅  
U+2E05  Right dotted substitution bracket  ⸅  
U+2E09  Left transposition bracket  ⸉  ⸉...⸊  
U+2E0A  Right transposition bracket  ⸊  
U+2E0C  Left raised omission bracket  ⸌  ⸌...⸍  
U+2E0D  Right raised omission bracket  ⸍  
Medieval studies^{[45]}^{[49]}  U+2045  Left square bracket with quill  ⁅  ⁅...⁆ 
U+2046  Right square bracket with quill  ⁆  
U+2E26  Left sideways u bracket  ⸦  ⸦crux⸧  
U+2E27  Right sideways u bracket  ⸧  
U+2E28  Left double parenthesis  ⸨  ⸨...⸩  
U+2E29  Right double parenthesis  ⸩  
Quotation (EastAsian texts)^{[54]} 
U+3014  Left tortoise shell bracket  〔  〔...〕 
U+3015  Right tortoise shell bracket  〕  
U+3016  Left white lenticular bracket  〖  〖...〗  
U+3017  Right white lenticular bracket  〗  
U+3018  Left white tortoise shell bracket  〘  〘...〙  
U+3019  Right white tortoise shell bracket  〙  
U+301A  Left white square bracket  〚  〚...〛  
U+301B  Right white square bracket  〛  
U+301D  Reversed double prime quotation mark  〝  〝...〞  
U+301E  Double prime quotation mark  〞^{[e 2]}  
Quotation (halfwidth EastAsian texts)^{[38]}^{[55]} 
U+2329  Leftpointing angle bracket  〈 ⟨^{[e 1]}  〈deprecated〉 
U+232A  Rightpointing angle bracket  〉 ⟩^{[e 1]}  
U+FF62  Halfwidth left corner bracket  ｢  ｢ｶﾀｶﾅ｣  
U+FF63  Halfwidth right corner bracket  ｣  
Quotation (fullwidth EastAsian texts)^{[54]} 
U+3008  Left angle bracket  〈  〈한〉 
U+3009  Right angle bracket  〉  
U+300A  Left double angle bracket  《  《한》  
U+300B  Right double angle bracket  》  
U+300C  Left corner bracket  「  「表題」  
U+300D  Right corner bracket  」  
U+300E  Left white corner bracket  『  『表題』  
U+300F  Right white corner bracket  』  
U+3010  Left black lenticular bracket  【  【表題】  
U+3011  Right black lenticular bracket  】  
General purpose (fullwidth EastAsian)^{[55]} 
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)^{[55]} 
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  ｝  
U+FF5F  Fullwidth left white parenthesis  ｟  ｟...｠  
U+FF60  Fullwidth right white parenthesis  ｠ 
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,^{[38]} 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.
A sign } used in writing or printing, chiefly for the purpose of uniting together two or more lines, words, staves of music, etc. Sometimes, but less correctly, used in plural to denote square brackets [ ].