Guidelines for using parentheses
Parentheses are one form of punctuation that can cause some confusion. Some people have trouble determining when to use them, while others may apply them without really knowing if parentheses are the most appropriate punctuation.
Use parentheses to set off nonessential elements in a sentence. Example: We will need to clean out Julia’s desk (she resigned last week) before her replacement starts on Monday.
Use parentheses to enclose information that is independent of the main sentence. Example: Our new office in Miami has much more open space than our previous location (in Orlando).
For better clarity, use parentheses instead of commas when the information you want already contains commas. Example: All administrative assistants (Mary, Joanne, Gerry and Cory) have asked to take vacation at the same time.
Do not place punctuation such as commas, semicolons or dashes before an opening parenthesis or before the closing parenthesis unless in relates only to the material in the parentheses. Wrong: We’ll order our typical refreshments: (pizza, salad, cookies and soda) for tomorrow’s meeting. Often dashes can be used to set off parenthetical phrases. Example: We’ll order our typical refreshments—pizza, salad, cookies and soda—for tomorrow’s meeting.
Do not capitalize the first word of a phrase inside parentheses unless it’s a proper noun or it is a complete sentence. Example: Please reply by Sept. 30, 2016. (A post-paid envelope is enclosed.)