Commas

Q. I’m editing a contract with many lists in it. After the recent court case involving the serial comma, I am trying to be even more diligent. I am sure at one point I read that if you have a list with items separated by the word or, you do not need a comma. I have looked through the entire comma, list, and conjunction sections of CMOS, but do not see any guidance. Which is correct? Here’s an example: I will eat pasta or pizza or salad. I will eat pasta, or pizza, or salad. Thank you in advance!

A. You will find what you’re looking for at CMOS 6.19: “In a series whose elements are all joined by conjunctions, no commas are needed unless the elements are long and delimiters would be helpful.” This doesn’t mean that commas are forbidden when the elements are short, however. In some cases where pauses are needed, they may be appropriate.

[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]