Bracket Symbols Complete Guide | Reference Chart & Input Tutorial

Bracket symbols are indispensable paired delimiters in writing, math, and programming. They group elements, define ranges, indicate function parameters, or array indices. This page compiles all bracket types—round ( ), square [ ], curly { }, angle 〈 〉, tortoise shell 〔〕, hollow 〖〗, and various special/math brackets—with detailed usage, Unicode, LaTeX commands, and HTML entities for quick reference in academic writing, coding, and typesetting.

🔤 1. Basic Brackets (Round, Square, Curly)

( is the left parenthesis, used for grouping in math, function parameters, or indicating precedence. Unicode: U+0028, LaTeX: input ( directly, HTML entity: (. In programming, it also invokes functions and controls statement structure. In regex, parentheses capture subexpressions.

) is the right parenthesis, paired with the left to close groups or parameter lists. Unicode: U+0029, LaTeX: ), HTML entity: ). In LaTeX math, use \left( \right) to auto-scale height.

[ is the left square bracket, common in array indexing, list access, and math intervals (closed interval). Unicode: U+005B, LaTeX: [, HTML entity: [. In Markdown/Wiki, it often denotes links or references. In Python, it's used for list definition and slicing.

] is the right square bracket, closing arrays or intervals. Unicode: U+005D, LaTeX: ], HTML entity: ]. In coding, curly and square brackets combine for multi-dimensional arrays.

{ is the left curly brace, also called curly bracket. In programming, it defines code blocks, object literals, and sets. Unicode: U+007B, LaTeX: \{ (escaped), HTML entity: {. In math, it represents sets, e.g., {x | x > 0}.

} is the right curly brace, paired with the left. Unicode: U+007D, LaTeX: \}, HTML entity: }. JSON heavily relies on curly braces for data structure. In LaTeX, they group commands and limit scope.

📐 2. Math-Specific Brackets (Double Square, Hollow Brackets, etc.)

⟦ is the left white square bracket, used in math for integer parts, polynomial rings, or special semantics. Unicode: U+27E6, LaTeX: \llbracket (requires stmaryrd or mathtools package), HTML entity: ⟦. Common in abstract algebra and number theory.

⟧ is the right white square bracket, paired with ⟦. Unicode: U+27E7, LaTeX: \rrbracket, HTML entity: ⟧. Less common than standard brackets but has specific uses in denotational semantics.

⦃ is the left hollow curly bracket, a variant with less internal strokes, used to distinguish semantic levels. Unicode: U+2983, HTML entity: ⦃. No direct LaTeX command; use \symbol{2983} or unicode-math.

⦄ is the right hollow curly bracket, paired with ⦃. Unicode: U+2984, HTML entity: ⦄.

⦅ is the left hollow square bracket, a hollow variant. Unicode: U+2985, HTML entity: ⦅. Used when multiple bracket layers need distinction.

⦆ is the right hollow square bracket, paired with ⦅. Unicode: U+2986, HTML entity: ⦆.

⦇ is the left hollow parenthesis, a hollow version. Unicode: U+2987, HTML entity: ⦇. Introduces new bracket layers in advanced typesetting.

⦈ is the right hollow parenthesis, paired with ⦇. Unicode: U+2988, HTML entity: ⦈.

⧼ is the left indeterminate bracket, shape between angle and curly. Unicode: U+29FC, HTML entity: ⧼. Occasional in logic and set theory.

⧽ is the right indeterminate bracket, paired with ⧼. Unicode: U+29FD, HTML entity: ⧽.

⌨️ 3. Angle & Corner Brackets (Guillemets, Math Angle Brackets)

⟨ is the left mathematical angle bracket, used for inner products, ordered pairs, or expectation values. Unicode: U+27E8, LaTeX: \langle, HTML entity: &#10216;. Distinguish from less-than sign <; angle is sharper. Use \left\langle \right\rangle for auto-scaling.

⟩ is the right mathematical angle bracket, paired for inner products or closing references. Unicode: U+27E9, LaTeX: \rangle, HTML entity: &#10217;. Dirac bra-ket notation in quantum mechanics heavily uses these, e.g., ⟨ψ| and |ψ⟩.

〈 is the left angle bracket (inner CJK book title mark), used in East Asian typesetting for titles or marking. Unicode: U+3008, LaTeX: \textlangle (textcomp package), HTML entity: &#12296;. In Chinese horizontal text, it nests inside 《》 for book titles.

〉 is the right angle bracket, paired to close title marks. Unicode: U+3009, LaTeX: \textrangle, HTML entity: &#12297;.

《 is the left double angle bracket, used as outer book title mark in Chinese/East Asian languages. Unicode: U+300A, LaTeX: input directly or use CJK package, HTML entity: &#12298;. Indicates titles of books, films, articles. In mainland China standard, 《》 is outer, 〈〉 is inner.

》 is the right double angle bracket, paired to end title marking. Unicode: U+300B, HTML entity: &#12299;. Sometimes used as decorative quote boxes on social media (non-standard).

‹ is the single left-pointing angle quotation mark, used as single guillemet or special citation mark. Unicode: U+2039, LaTeX: \guilsinglleft, HTML entity: &#8249;. More common in European language typesetting.

› is the single right-pointing angle quotation mark, paired with ‹. Unicode: U+203A, LaTeX: \guilsinglright, HTML entity: &#8250;. Used as inner quotation nesting in some European languages.

🇨🇳 4. Chinese/East Asian Brackets (Tortoise Shell, Hollow, Black Lenticular)

【 is the left black lenticular bracket, also called left solid square-head bracket. Used in Chinese typesetting for headings, emphasis, or highlighting; very common in notes, outlines, and scripts. Unicode: U+3010, HTML entity: &#12304;. LaTeX: \text{【} (requires CJK support). Visually bolder than standard square brackets.

】 is the right black lenticular bracket, closing the emphasis area. Unicode: U+3011, HTML entity: &#12305;. In Korean and Japanese text, used for annotations or marking. In Chinese online communities, often used as topic tags or category markers.

〔 is the left tortoise shell bracket, with a more rounded shape than square brackets. Used in Chinese official documents for annotations, file numbers, or special marks. Unicode: U+3014, HTML entity: &#12308;. LaTeX: \text{〔}. In mainland China official document format, 〔〕 often marks document reference numbers.

〕 is the right tortoise shell bracket, paired with 〔. Unicode: U+3015, HTML entity: &#12309;. Less frequent than parentheses in standard Chinese typesetting but holds a specific role in formal documents.

〖 is the left hollow bracket, also called left white bracket. Decorative appearance, used in ancient book typesetting, special marking, or when distinguishing multiple bracket nesting layers. Unicode: U+3016, HTML entity: &#12310;. LaTeX: \text{〖}.

〗 is the right hollow bracket, paired with 〖. Unicode: U+3017, HTML entity: &#12311;. Rare in modern typesetting but common in traditional vertical text and classical book reproductions.

〘 is the left solid double bracket, featuring a double-layered square bracket appearance. Used in vertical CJK typesetting and special marking scenarios. Unicode: U+3018, HTML entity: &#12312;. Very rare in modern horizontal text; a historical symbol for East Asian vertical typesetting.

〙 is the right solid double bracket, paired with 〘. Unicode: U+3019, HTML entity: &#12313;.

〚 is the left hollow double bracket, with more white space than the solid version. Unicode: U+301A, HTML entity: &#12314;. Used in traditional ancient books or vertical typesetting special marks.

〛 is the right hollow double bracket, paired with 〚. Unicode: U+301B, HTML entity: &#12315;. Extremely rare in modern daily use; primarily ensures vertical CJK character completeness in Unicode.

「」 5. Corner Quotation Brackets (CJK Right-Angle Quotes)

「 is the left corner bracket, also called left right-angle quotation mark. In Japanese and Traditional Chinese, it serves as the primary opening quotation mark, similar to English left double quote. Unicode: U+300C, HTML entity: &#12300;. LaTeX: \text{「}. Widely used in Taiwan, Hong Kong, and Japan formal typesetting instead of curly quotes.

」 is the right corner bracket, paired with 「 to close quotation. Unicode: U+300D, HTML entity: &#12301;. Corner brackets maintain good symmetry in both horizontal and vertical text due to their square, clean appearance.

『 is the left white corner bracket, used for second-level quotation or inner book title marks in Japanese and Traditional Chinese. When 「」 needs nesting, outer uses 「」, inner uses 『』. Unicode: U+300E, HTML entity: &#12302;. In Japanese typesetting, 『』 is also directly used as book title marks.

』 is the right white corner bracket, closing nested quotation. Unicode: U+300F, HTML entity: &#12303;. In Chinese typesetting, quotation nesting should not exceed two levels; if a third level is needed, rewrite to avoid it.

〝 is the left double quotation bracket, also called vertical left double prime mark. Primarily used for double quotation marks in vertical text. Unicode: U+301D, HTML entity: &#12317;. Rarely used in horizontal text; appears mainly in traditional East Asian vertical typesetting.

〞 is the right double quotation bracket, paired with 〝 for vertical citations. Unicode: U+301E, HTML entity: &#12318;. Note that most modern fonts and rendering engines have limited support for vertical quotation marks.

📏 6. Fullwidth & Superscript/Subscript Brackets

﹙ is the fullwidth left parenthesis, occupying one Chinese character width, used in Chinese fullwidth typesetting. Unicode: U+FE59, HTML entity: &#65113;. Directly inputtable in Chinese IME fullwidth mode, ensuring alignment with Chinese character width.

﹚ is the fullwidth right parenthesis, paired with ﹙. Unicode: U+FE5A, HTML entity: &#65114;.

﹛ is the fullwidth left curly bracket, occupying one Chinese character width. Unicode: U+FE5B, HTML entity: &#65115;. In Chinese technical document typesetting, fullwidth curly brackets visually align with Chinese characters.

﹜ is the fullwidth right curly bracket, paired with ﹛. Unicode: U+FE5C, HTML entity: &#65116;.

⁅ is the superscript left square bracket, used for special marking in math or linguistics. Unicode: U+2045, HTML entity: &#8261;. No direct LaTeX command; use \textsuperscript{[} or special packages.

⁆ is the superscript right square bracket, paired with ⁅. Unicode: U+2046, HTML entity: &#8262;.

⁽ is the superscript left parenthesis, used in math formula superscripts. Unicode: U+207D, HTML entity: &#8317;. Common in chemical formulas and mathematical exponent expressions.

⁾ is the superscript right parenthesis, paired with ⁽. Unicode: U+207E, HTML entity: &#8318;.

₍ is the subscript left parenthesis, used in math formula subscripts. Unicode: U+208D, HTML entity: &#8333;. Used in sequences, chemical formulas, etc., with subscript contexts.

₎ is the subscript right parenthesis, paired with ₍. Unicode: U+208E, HTML entity: &#8334;.

💡 7. Bracket Usage Summary

1. Math Formula Bracket Precedence: Typically follows parentheses ( ) > square brackets [ ] > curly braces { } nesting order, though complex expressions often use multiple nested parentheses for clarity. In LaTeX, use \left( \right) for auto-scaling, and \big, \Big, \bigg, \Bigg commands for manual sizing.

2. Programming Bracket Rules: Each language has strict bracket syntax. Parentheses ( ) for function calls and control conditions, square brackets [ ] for array indexing, curly braces { } for code blocks and object definitions. The three cannot be mixed; most modern IDEs provide bracket matching highlighting and auto-completion.

3. Chinese Typesetting Bracket Selection: Standard Chinese body text recommends fullwidth brackets (e.g., （）【】《》) to match Chinese character width. Tortoise shell brackets 〔〕 are mainly for official document reference numbers and special annotations. Book title marks 《》 indicate work titles, with inner nesting using single angle brackets 〈〉. Black lenticular brackets 【】 are common for headings and emphasis.

4. Paired Bracket Usage: All bracket symbols must appear in pairs with strict left-right matching. In Chinese IME, press Shift to toggle fullwidth/halfwidth brackets. This page provides Unicode codes, LaTeX commands, HTML entities, one-click copy, and SVG/PNG download for all bracket symbols, helping you quickly use the correct brackets in academic papers, technical documents, and design works.