General guidance on the use of punctuation
Symbol |
Guidance |
Example |
Brackets/parentheses
|
UK English: use round brackets throughout for nested brackets. US English: use round brackets followed by square brackets for nested brackets. |
UK English: The standardized mean difference was -0.02 (95% confidence interval (CI) -0.13 to 0.08). US English: The standardized mean difference was -0.02 (95% confidence interval [CI] -0.13 to 0.08). |
Square brackets may be used in chemical formulae, mathematical formulae, edits to quotations, or to indicate an error in the original version of quotation. |
pH = -log10 [H+] … as Jones said, "there are very few people who are resistant to [morphine]." (where morphine replaces 'this medication' to ensure contextual accuracy) Smith says "students tend to overlook there [sic] health". |
|
Colon
|
Follow a colon with a lower-case letter unless the following word has to start with an upper-case letter. |
Review topic: cancer Review topic: HIV/AIDS |
Comma
|
Use of a comma before ‘and’ and ‘or’ in lists is optional, but be consistent. |
I have read Cochrane Reviews about malaria, tuberculosis, and vaccines. I have read Cochrane Reviews about malaria, tuberculosis and vaccines. |
Use commas before ‘and’, ‘or’, and ‘but’ in two-phrase sentences (when these words join the two main clauses). |
The reviews are written here, but they are available internationally. The reviews are sent here by post, or they are sent here electronically. |
|
Dash |
There should be one space either side of a dash. |
The reviews are sent here by post – or electronically – and then processed. |
Full stop |
Use one space (not two) after the full stop. Note: when the publishers format Cochrane Reviews, one space is allocated after each full stop. This means if you use two spaces, they will be reduced to one. |
|
Hyphen |
Hyphens are used to link two or more word compounds used as adjectives, such as ‘six-week interval’ and ‘four-dose regimen’. Be aware that hyphens can sometimes change the meaning of a word, such as ‘unionized’ (with a union) and ‘un-ionized’ (without ions). |
There was a six-week interval between doses. |
Period |
See full stop |
|
Quotation marks
|
Use double quotation marks for quoting dialogue and when quoting text from a written source. No other formatting is required for quotations (do not use italics). |
In the study “12 participants experienced adverse effects” (Goodwin 1998). |
Use single quotation marks in all other instances. |
The ‘standard’ approach is to count only major events. |