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.
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
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.
Practical Application
Use parentheses for ordinary parenthetical material. Use square brackets for editorial insertions, nested functions, or other bracket-specific purposes required by the governing style. Choose by function, not appearance.
Reader Check
Are you adding an aside from the original writer, or inserting/editing material inside quoted or already-parenthetical text? Check the applicable style for that context.
Worked Example
Ordinary aside: “The report (revised in June) is final.” Editorial insertion in a quotation: use square brackets for the inserted clarification when the governing style calls for them.
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.
- Formatting punctuation — Microsoft Style Guide (opens in a new tab)Microsoft · Microsoft house-style guidance for formatting parentheses and brackets
- 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