Writing & StyleStyle guide

Parentheses vs. Square Brackets

Parentheses and square brackets should not be swapped merely for appearance. Professional styles commonly use parentheses for parenthetical material and square brackets for functions such as editorial insertions or nested parenthetical material; exact conventions should follow the governing style guide.

Quick answer

Use parentheses for ordinary parenthetical material; use square brackets for editorial insertions or other bracket-specific functions required by the style and context.

Key details

Core IssueParentheses and square brackets are distinct marks: parentheses commonly set off parenthetical material, while square brackets have editorial and nesting uses that depend on style and context.
Phrase Roleprofessional-writing and typography guidance
Registerprofessional, technical, and editorial writing

Important caveats

Style Boundary

Square-bracket conventions vary by editorial context, including quotation editing and nested punctuation, so follow the applicable house or publication style.

Further guidance

Brackets

Chicago uses square brackets for editorial insertions, illustrating a distinct editorial function rather than a decorative substitute for parentheses.

Parentheses

Parentheses are the ordinary round marks used to enclose parenthetical material; their formatting should follow the main-text style unless a house style says otherwise.

Sources and evidence

Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.

  1. Formatting punctuation — Microsoft Style Guide (opens in a new tab)Microsoft · Microsoft house-style guidance for formatting parentheses and brackets
  2. Chicago Manual of Style Q&A: editorial insertions in square brackets (opens in a new tab)The Chicago Manual of Style · Chicago guidance showing square brackets for editorial insertions

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