5.6.5 Brackets and Slashes

Four main kinds of brackets are used in formal English prose: ‘( )’ are called ‘parentheses’ or sometimes ‘parens’ and more casually ‘round brackets’; ‘[ ]’ are referred to as ‘square brackets’ in British English but in most cases simply as ‘brackets’ in American English; ‘{ }’ are formally called ‘braces’ but informally known as ‘curly brackets’; and ‘< >’ are referred to as ‘angle brackets.’ Each type of bracket has particular though occasionally overlapping functions in academic and scientific prose, with some of those functions highly specialised in certain disciplines. Braces and angle brackets, for instance, have particular meanings and uses in mathematics, computing, music, economics, prosody, etymology, textual editing and typesetting. In this section, I focus on the uses of brackets that tend to apply to writing in more general scholarly contexts, and thus on the two types of brackets most commonly used in running prose – parentheses and square brackets. For detailed advice on the specialised use of these and other brackets in particular disciplines, see, for example, the chapters on science, mathematics, computing, law, music and other subjects in New Hart’s Rules (Ritter, 2005, Chapters 13 and 14), Butcher’s Copy-Editing (Butcher et al., 2006, Chapter 13 and Sections 14.2 and 14.3) and the Chicago Manual of Style (2003, Chapter 14).

Parentheses. Round brackets or parentheses (the singular is ‘parenthesis’) tend to be used more frequently than other brackets in most formal writing. In the running text of scholarly prose, they are used to enclose parenthetical material, specifically information that is less closely related to the rest of the sentence than is parenthetical material set off by commas, en rules or em rules: ‘I discovered (much to my chagrin!) that I was being paid half of what other nurses were earning’ and ‘The original version of the novel (written almost two decades earlier) did not contain this passage.’ Glosses and translations can be enclosed within them: ‘joie de vivre (joy of living),’ ‘joy of living (joie de vivre)’ and ‘his words were “sed noli modo (but not now)”’ (see also Section 8.4). When titles are translated in this way, any special font used on the title should be used for the translation as well: ‘De Libero Arbitrio (On Free Will),’ and notice that, according to the principles for using italic font (see Section 6.2.2), the parentheses could appear in either italics or roman font as long as both parentheses in a set use the same font and similar situations are treated in the same way throughout a thesis.

Sometimes square brackets are used instead of parentheses to enclose title translations, particularly in the full bibliographical references for some referencing styles: ‘De Libero Arbitrio [On Free Will].’ Parentheses are also used around other aspects of full bibliographical references (dates, publication information and issue numbers, for instance) in both reference lists and notes, and they are used in running text to enclose in-text references in author–date systems of referencing: ‘(Bennett, 2006; Vanhoof, 2010).’ Notice that when separating references and other main components of information (statistical data, for example) in parentheses, semicolons are generally used – ‘(for the men, the best time was 67 ms and the worst 89 ms; for the women, the best time was 65 ms and the worst 92 ms)’ – though commas are acceptable for separating items that are short and do not contain internal punctuation, such as the dates of different publications by the same author in author–date in-text references: ‘(Vanhoof, 1989, 1997, 2002, 2010).’ See Section 5.6.1 on commas and semicolons, and for more information on the use of parentheses in references, see Chapter 7.

Parentheses are also used when introducing and defining nonstandard abbreviations of all kinds – ‘participants who completed Questionnaire 2 (Group Q2),’ ‘Times Literary Supplement (TLS)’ and ‘American Medical Association (AMA).’ Generally, as in these examples, the full term comes first, but the order can be reversed – ‘AMA (American Medical Association)’ – which is handy for referencing because the abbreviation can be cited in the main text and then precede the full version in the reference list, which makes finding an abbreviated source straightforward for your reader (see Sections 6.3 and 7.2.1). Variants, explanations, alternative spellings and other supplementary information are often enclosed in parentheses: for example, ‘the correct form is “programme” in British English (but “program” for computer software)’ and ‘much of the Findern Manuscript (late fifteenth century) appears to have been written by female scribes, who may also have authored some of the poems.’ In lists, parentheses often surround item numbers, particularly if the list is presented in running text: ‘Four conditions were created for the test: (1) darkness inside, (2) darkness outside, (3) artificial lighting inside and (4) daylight outside.’ In such a list, a pair of parentheses enclosing each number is clearer than and preferable to a single closing parenthesis after each number.

Lists, tables and figures can contain a variety of information in parentheses, which are particularly effective for separating different measurements and kinds of data (such as number and percentage), even within the narrow column of a table: ‘34(50%)’ in one row, ‘17(25%)’ in the next and ‘17(25%)’ in another. Most parenthetical material needs to correspond with what has immediately preceded it in terms of both content and grammar, so 34 participants and 50% of the sample are equivalent in the example above, and such equivalence should exist between what comes before the parentheses and what is presented within them in other cases as well: for instance, ‘the examples above (parenthetical clauses, translations, abbreviations etc.)’ is correct, but ‘the examples above (the one for translation)’ is not, and ‘in that year (1996)’ is appropriate, but ‘in that year (1996–1999)’ is not.

In British English, parentheses can be used within parentheses in normal running prose when necessary: ‘(34 men (50%) and 34 women (50%)).’ In American English, however, square brackets are generally used within parentheses – ‘(34 men [50%] and 34 women [50%])’ – and, if necessary, parentheses are then used within those interior square brackets, square brackets within those and so on. Whichever form of English you are using, it is usually best to keep double bracketing to a minimum, especially in the main text of a thesis, where rewording or rearranging parenthetical material to avoid double bracketing is often a preferable option. Similarly, it is best if parentheses do not appear back to back, and if they must, that this be kept to a minimum, a principle that applies to all brackets in general contexts, but some specialised uses may require this format, just as they may require a specific order for brackets: see, for instance, Butcher et al. (2006, pp.319–320) and Ritter (2005, Section 14.6.5) for the order of brackets in mathematics, and see also Ritter (2005, Chapter 13) on the conventions for using parentheses and square brackets in legal contexts.

Punctuation in relation to parentheses is relatively straightforward. Parentheses can be used within dashes (en rules and em rules) and dashes within parentheses: ‘three kinds of birds returned in the spring – robins, chickadees (the smallest) and sparrows – and left again in the fall’ or ‘three kinds of birds returned in the spring (robins, chickadees – the smallest – and sparrows) and left again in the fall.’ A comma or semicolon should precede an opening parenthesis only in the enumeration of a list – ‘Four conditions were created for the test: (1) darkness inside, (2) darkness outside, (3) artificial lighting inside and (4) daylight outside’ – and neither should ever precede a closing parenthesis. ‘After crawling through the window (on the third floor), she unlocked the door’ demonstrates the correct way to punctuate if a sentence requires a comma at the end of a set of parentheses; ‘After crawling through the window (on the third floor,) she unlocked the door’ is incorrect, and notice that ‘After crawling through the window, (on the third floor) she unlocked the door’ bears a different meaning. In such a construction, the comma properly belongs to the surrounding sentence, not to the parenthetical material, so should appear after the closing parenthesis. Full stops as well as question and exclamation marks (see Section 5.6.2) behave in the same way, following the closing parenthesis if they belong to the sentence as a whole and preceding the closing parenthesis only if they belong particularly or solely to the parenthetical material: for example, ‘I worked for days to polish my thesis, yet my external examiner had the audacity to say something truly insulting (“It doesn’t look like you proofread this at all”)!’ but ‘It may be November, but it was as warm as summer yesterday (can you believe it?).’ In the case of a full stop, ‘belonging’ to the parenthetical material means that the parenthetical material forms a complete sentence and the parenthetical construction as a whole is separate from other sentences, as the final sentence of this paragraph is. (For this reason, one or more full sentences within parentheses should never be embedded in another sentence.)

Square brackets. As mentioned above, square brackets are used in American English for parenthetical material that is already enclosed in parentheses, but their more common use in both British and American English is to enclose material that an author adds to a quotation, whether to make the quotation work in his or her own prose or to correct, comment on, translate or otherwise explain aspects of the quotation: ‘the book has been called “a library in parvo [in small]” because its contents are both numerous and diverse’ (further examples and discussion can be found in Sections 8.3 and 8.4). Square brackets are usually not used around ellipsis points that are added to indicate omissions from quotations, but in rare cases strict guidelines or the material quoted will require the use of brackets: ‘Whan that Aprill [ . . . ] hath perced’ instead of the more usual ‘Whan that Aprill . . . hath perced’ (Kolve & Olson, 1989, ‘General Prologue’ 1–2; see Section 8.3 ). Punctuation rules in relation to square brackets in running text are exactly as they are for parentheses (see above). Square brackets can be used to enclose numerical in-text references and occasionally to enclose parenthetical author–date references, and in the full bibliographical references found in lists, they can be used to surround translated titles and to enclose information (author names, dates etc.) that does not actually appear in the source itself, but is known from elsewhere (see Chapter 7).

The forward slash. The slash (/), also known as a ‘solidus,’ ‘slant,’ ‘stroke,’ ‘virgule,’ ‘oblique,’ ‘diagonal,’ ‘shilling mark’ or ‘forward slash’ to distinguish it from a backward or back slash (\), has a number of specific uses in formal prose. These include

• Expressing alternatives, in which the slash basically means ‘or’: ‘and/or,’ ‘his/her,’ ‘s/he,’ ‘on/off’ and the like. In most instances, no spaces appear around the slash in such situations, but if one or both of the alternatives is a compound, particularly an unhyphenated compound, spaces may be helpful: ‘World War I / First World War,’ but ‘mother-in-law/father-in-law.’ Sometimes an en rule takes the place of a slash: ‘an either–or situation’ (on the en rule, see Section 5.6.4 above).
• Representing the word ‘and,’ as in ‘a Jekyll/Hyde personality,’ but this is rare and, as a general rule, such cases are better with the word ‘and’ instead of the slash (a Jekyll and Hyde personality). No spaces are used around the slash.
• Separating the locations on a route (with the meaning ‘to’) or defining a meeting place or close relationship (with the meaning ‘and’), especially if either or both of the elements concerned consist of more than one word, as in ‘the Tsawwassen/Swartz Bay ferry crossing,’ ‘the Canada/United States border’ and ‘red/green colour blind,’ but an en rule is the more common choice in all these instances (see Section 5.6.4 above). No spaces are used around the slash.
• Specifying a year that extends over more than one calendar year – ‘2011/12’ – sometimes in combination with an en rule in a range of years: ‘2011/12– 2014/15.’ No spaces are used around the slash.

• Punctuating all-numeral dates (13/09/59), although this format for dates should be avoided if possible because it can be confusing (see the discussion of dates in Section 6.4.4 below). The shorthand ‘9/11’ is frequently used to refer to the attack on the World Trade Center Towers in New York on 11 September 2001, but it is good to use the full date at least on first mention. No spaces are used around the slash.
• Punctuating certain abbreviations, such as the commonly used ‘n/a’ (meaning ‘not applicable’), ‘c/o’ (meaning ‘care of’) and ‘24/7’ (meaning ‘24 hours a day, 7 days a week’). No spaces are used around the slash.
• Indicating ratios, with the meaning of the slash being ‘per’: ‘$125/day,’ ‘miles/hour’ and ‘precipitation/year.’ Here, too, there should be no spaces around the slash.
• Representing a fraction bar meaning ‘divided by’: for example, ‘3/5’ and ‘7/8.’ No spaces appear around the slash.
• Indicating the original line breaks when quoted poetry runs on in a single line in prose: ‘Whan that Aprill with his shoures sote / The droghte of Marche hath perced to the rote’ (Kolve & Olson, 1989, ‘General Prologue’ 1–2). In some styles a vertical line (|) is used for this purpose instead. Whichever is used, a space should appear on either side of it.
• Separating elements in URLs, where both single and double slashes are used without spaces as they are in the URL for the PRS web site: ‘http://www.proof-reading-service.com/.’ Both forward and backward slashes are also used in other aspects of computing.

PRS Tip: Although you may proofread your thesis several times with both your mind and your eyes focussed on details of various kinds, there are always numerous elements to consider in a thesis, and many of them can slip past unnoticed as you hasten through large chunks of complex text. The smaller the elements you are checking, the greater the chances of their being passed over, and problems with punctuation are certainly among the smallest and therefore most easily overlooked aspects of scholarly writing. A full stop is tiny, after all, as is a comma, and a semicolon looks much like a colon just as an en rule looks much like an em rule when there is no time to do more than glance at these bits of your text as you read for larger concerns, such as the argument and the accuracy of data. Missing such details is not at all unusual and definitely not a sign of deficiency on your part; in fact, it is normal for academic and scientific writing to undergo many revisions and a myriad of small corrections before it is finished, and, sadly, even for errors to remain in the final published versions of scholarly books and articles. In addition, you simply may not have the time, the patience or the inclination to devote exacting attention to each and every piece of punctuation in your writing, but all aspects of the punctuation in a doctoral thesis need to be correct, clear and effective in order to maintain a scholarly voice and communicate your meaning to your readers and examiners. Fortunately, the professional proofreaders at PRS do have the time, patience and inclination to check every bit of your punctuation for accuracy, consistency and suitability in the context, and they can do the same for many other elements, both small and large, of your writing. Once you have honed your thesis into a form you find satisfactory, send it on to PRS for a final polishing – you may well be surprised by the significant improvements a proofreader who specialises in scholarly English writing can make.