Q. I write professional resumes, and I have a question about the use of a comma in a sentence with including. My proofer has begun inserting a comma prior to including followed by a list: “Managed a variety of projects, including joint, combined, and contingency exercises.” Should this comma be omitted?

A. Many readers write to ask whether the word including always requires a comma in front of it, but there’s no simple answer. Each instance must be decided individually, because a comma changes the meaning.

I invited all the clubs including biker chicks and pit tootsies.

I invited all the clubs, including biker chicks and pit tootsies.

The first sentence is ambiguous; it might mean that I invited only clubs that include biker chicks and pit tootsies among their members. The second sentence makes clear that I invited all clubs, regardless of membership, and that this included the chicks’ and tootsies’ clubs. In your text you need a comma if the chunk after including is nonrestrictive (that is, if some of the projects included joint exercises, some included combined, some both, etc.). Without a comma, including becomes restrictive, and the implication is that every project included joint, combined, and contingency exercises.

You can read more about restriction by typing restrictive into the search box at the CMOS Q&A site.