There can be plenty of brackets and parentheses in legal citations. Yet, a case citation is incomplete unless it also includes the year of the decision. If a decision has a neutral citation, the year is already part of the citation and there are no brackets or parentheses to worry about, e.g., 2011 ONCA 55. That’s the easy part.
Confusion can arise when a decision does not have a neutral citation and you are citing to a law report. Should the year appear in square brackets, round parentheses, or both? This is a brief guide to the rules on brackets and parentheses for Canadian neutral citations.†
The square bracket rule:
A handful of Canadian law reports organize their volumes by year and then by number within the year. For example,  3 SCR 725 indicates the case is included in the third volume of judgments for 2005.
If the year of the reporter and the year of the decision are the same, provide the year of the reporter. (McGill Guide, 8th ed., 3.4)
Example: Pan-Tax Inc v Revenue Canada,  2 CTC 315.
The year of the decision is shown as part of the law report citation, so there is no need to add the year in round brackets.
The round parentheses rule:
The majority of Canadian law reports have consecutively numbered volumes. The volume numbers begin at 1 and run until the publisher decides to start a new series. With these reports you need to add the year of the decision in parentheses directly after the name of the case (style of cause).
If the year of the reporter is not indicated, provide the year of the decision in parentheses. (McGill Guide, 8th ed., 3.4)
Example: Doxtator v French (2002), 59 OR (3d) 564.
When you need to use both:
Most cases are decided and published in the same year. However, what happens if a decision is handed down late in the year and is not published in a law report until the following year? Since it is the year the case was decided that matters to your reader, you must include it in parentheses where necessary.
If the year of the reporter and the year of the decision are different, provide both years. (McGill Guide, 8th ed., 3.4)
Example: R v Amway of Canada (1986),  1 FC 3.
So, simply put:
- Square brackets = the year the case was published.
- Round parentheses = the year the case was decided.
A tip to help remember the rules:
Think of [square brackets] as book covers. This will help you associate these brackets with the actual volume, and remember that they form part of a law report citation. (Round parentheses) with the year are added by you, the writer, to citations that do not show the year of the decision.
† These rules apply to Canadian neutral citations. The UK and many other Commonwealth countries’ neutral citations use square brackets around the year, e.g.,  EWHC 2714.