Here are some general guidelines:
Use a comma before parentheses if:
* The parenthetical phrase is an aside or non-essential information:
* "The meeting, (which was held in the conference room), was productive."
* The parenthetical phrase explains or clarifies a preceding word or phrase:
* "The company has a strict policy against smoking (including e-cigarettes)."
Do not use a comma before parentheses if:
* The parentheses enclose a number or letter that is part of a list or series:
* "The project has three main stages: (1) planning, (2) implementation, and (3) evaluation."
* The parentheses enclose a word or phrase that is essential to the meaning of the sentence:
* "The book (entitled 'The Hitchhiker's Guide to the Galaxy') is a popular science fiction classic."
* The parentheses enclose a date or time:
* "The meeting will be held on January 15, 2024 (10:00 AM - 12:00 PM)."
It's important to note that these are just general guidelines. Ultimately, the best way to determine whether or not to use a comma before parentheses is to consider the clarity and flow of the sentence.