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Style Manual

Brackets and parentheses

Brackets can make it easier for the user to scan text. Use brackets when it would not change the meaning if you removed enclosed text.

Use brackets for text users can skip over

Brackets can help you break up information. They enclose parts of the sentence that aren’t essential to the meaning. Sentences must be grammatically correct if you remove the text in brackets.

The most commonly used brackets are:

  • parentheses
  • square brackets.

Use brackets sparingly for:

Use brackets only where they make content clearer to people. For example, always use brackets in author–date citations.

Too many brackets, or badly used brackets, can make a sentence more complex and difficult to understand. You can usually rewrite a sentence so the content in brackets can be its own sentence or can even be removed.

Other types of brackets, such as curly brackets and slant brackets, are used in fields such as mathematics and linguistics. These are specialist uses, so don’t use them in most content.

Put extra information in parentheses

Information in parentheses is less important than information that is between spaced en dashes or pairs of commas.

Used well, parentheses can improve meaning and make content easy to scan.

Definitions

Parentheses enclose definitions.

Example

Medicare (Australia’s universal health insurance scheme) guarantees all Australians access to a wide range of health and hospital services.

Shortened forms

Parentheses introduce a shortened form after it has been spelt out in full. You can then use the shortened form through the rest of the page or publication.

Example

The National Health and Medical Research Council (NHMRC) is responsible for research funding and health guidelines.

Cross-references

Parentheses enclose cross-references to other parts of the content.

Example

Australia’s population increased by 350,000 people last year (Table 1).

Citations

Parentheses enclose citations in the author–date system of referencing.

Example

China is Australia’s largest trading partner (Smith 2019).

Extra detail

Parentheses enclose extra detail.

Example

Our 2 biggest exports are iron ore ($61.4 billion) and coal ($60.4 billion).

The winning tenderer (which was a local company) signed the contract on Tuesday.

Clarification and asides

Parentheses enclose text that doesn’t have a grammatical relationship to the rest of the sentence. This type of text includes extra information, clarifications and asides.

Example

The department was in a heritage-listed building. (The building was designed by award-winning architect Enrico Taglietti.)

Whitlam’s comments on the steps of Parliament House(‘Well may we say ...’) are still widely quoted.

Avoid using square brackets in parentheses

Reword the text to avoid square brackets inside of parentheses wherever possible.

Example

Australia’s Parliament House opened on 9 May 1988. The architects were Mitchell/Giurgola & Thorp (New York).

Don’t use sets of parentheses inside each other. Instead, use square brackets if you must put parenthetical information within parentheses.

Like this

Australia’s Parliament House (architects Mitchell/Giurgola & Thorp [New York]) opened on 9 May 1988.

Not this

Australia’s Parliament House (architects Mitchell/Giurgola & Thorp (New York)) opened on 9 May 1988.

Use square brackets to show insertions in quotes

Use square brackets in quoted material to show that you have:

  • paraphrased the original content
  • inserted text that was not in the original content.
Example

He wrote in the report, ‘The department’s executive moved into new offices in Barton [Canberra] last year.’

‘The High Court [in Canberra] is the highest court in the land,’ she said.

You can also use square brackets to clarify quoted material.

Example

The manager reported, ‘Smith was furious with Jackson because he [Smith] wanted all the credit.’

Square brackets with an italicised ‘sic’ show that the error in the text is from the original writer.

Example

Written late at night, the report began, ‘The office was previously in Melberne [sic].’

Follow normal punctuation rules for content in brackets

Punctuation in brackets depends on what is inside the brackets. Punctuate content in brackets as you would if it were outside the brackets.

Example

Whitlam’s comments on the steps of Parliament House (‘Well may we say ...’) are still widely quoted.

A comma follows a closing bracket only if you would have used a comma if there were no brackets.

Correct

The winning tenderer (a local company) signed the contract on Tuesday.

Incorrect

The winning tenderer (a local company), signed the contract on Tuesday.

If the content inside the brackets is a full sentence, include the end punctuation inside the brackets.

Example

The department was in a heritage-listed building. (The building was designed by award-winning architect Enrico Taglietti.)

Don’t use brackets to enclose a sentence within a sentence. Rewrite the text instead.

Correct

The winning tenderer signed the contract on Tuesday. They were a local company.

The winning tenderer (a local company) signed the contract on Tuesday.

Incorrect

The winning tenderer (They were a local company.) signed the contract on Tuesday.

Write brackets in the same type as the surrounding text

Brackets should be in the same type (roman, italics, bold) as the text around the brackets. This is regardless of the type of the text inside the brackets.

This is the same rule as for quotation marks.

Correct

The most recent review of defence policy (2016 Defence white paper) set the direction for the next 10 years. [In this example, the parentheses are not in italics because the surrounding text is not in italics.]

Incorrect

The most recent review of defence policy (2016 Defence white paper) set the direction for the next 10 years.

Release notes

The digital edition consolidates information about brackets and parentheses from the sixth edition.

It omits the information about angle brackets that was included in the sixth edition. Angle brackets were used to enclose URLs and this practice is no longer followed. Sources cited as evidence support this departure.

The Content Guide did not include guidance on brackets or parentheses.

About this page

Evidence

Oxford University Press (2016) ‘18.8.3 Resource locators’, New Oxford style manual, Oxford University Press, Oxford.
 
University of Chicago (2017) ‘6.8 Punctuation with URLs and email addresses’, Chicago manual of style, 17th edn, University of Chicago Press, Chicago.

References

Btb Translation Bureau (n.d.) ‘Punctuation’, The Canadian style, Btb Translation Bureau website, accessed 4 May 2020.

Content Design London (2019) ‘Top findings’, Content Design London readability guidelines, Content Design London website, accessed 30 March 2020.

Dixon JC and Bolitho B (2005–2019) Course notes and exercises: Editing and proofreading for the workplace, Centre for Continuing Education, Australian National University, Canberra.

Murphy EM with Cadman H (2014) Effective writing: plain English at work, 2nd edition, Lacuna, 2014.

\Perlman M (2017) ‘How to properly use [sic]’, Columbia Journalism Review, viewed 19 December 2019,

Perlman M (2017) ‘Pardon my parentheticals’, Columbia Journalism Review, viewed 19 December 2019,

Seely J (2001) Oxford everyday grammar, Oxford Paperback Reference.

Stilman S (2004) Grammatically correct, Writer’s Digest Books, 2004; revised and updated, 2010.

Truss L (2003) Eats, shoots and leaves: the zero tolerance approach to punctuation, Profile Books, London, 2003.

U.S. Government Publishing Office (2016) ‘8: punctuation’, Government Publishing Office style manual, U.S. Government Publishing Office, accessed 13 May 2020.

This page was updated Monday 21 September 2020.

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