Different types (shapes) of brackets have different uses.

Parentheses (round brackets)

Use round brackets (sparingly) to enclose comments or explanations in the text. Place the full stop inside the closing bracket if the brackets contain a full sentence:

All the data (including the pilot study results) were analysed.

Provide your data as an Excel file. (Note that other file types will not be accepted.)

Dashes can be used as an alternative to round brackets to enclose parenthetical information within a sentence.

If it is necessary to refer to the plural as an alternative to the singular, use parentheses around the s, but use this convention sparingly:

representative(s)     guideline(s)

Square brackets

Use square brackets:

  • when you need brackets within brackets (do not use round brackets within round brackets)

We used the alternative method (which was recommended in Smith [2012]).

  • to indicate an editorial comment, correction or clarification in quoted text

The team visited Aceh [Indonesia] and Sabah [Malaysia].

  • in mathematical expressions

y[(a – b) + (c – d)]

Curly brackets

Paired left and right curly brackets are used in mathematics and chemistry to enclose elements already enclosed by parentheses and square brackets:

x + {1 + [3 + 2 × (4 + 5)]}

In maths, a left curly bracket covering several lines is used for grouping:

\(f(x)=\begin{cases}x&\text{if }x\ge0\\-x&\text{if }x<0\end{cases}\)

Angle brackets

Angle brackets – ‘greater than’ and ‘less than’ symbols – are used to enclose meta text in HTML:

<p>Close the door, or else!</p>

[<p>indicates the start of a new paragraph; </p>ends the paragraph]