Comma Before Including
A comma before an “including” phrase is not automatic; punctuation can change whether the information is read as supplementary or restrictive. Chicago’s guidance makes the distinction depend on meaning, so avoid a mechanical rule that always inserts or always removes the comma.
Use commas around an “including” phrase when it is nonrestrictive or supplementary; omit the comma when the phrase is essential to identifying the intended set.
Key details
Important caveats
Scope Boundary
Chicago’s guidance makes the distinction depend on meaning, so avoid a mechanical rule that always inserts or always removes the comma.
Further guidance
Practical Application
Decide whether the “including” phrase is supplementary or essential to identifying the intended set. Set off a nonrestrictive phrase with commas; omit the comma when the phrase is necessary to define which members or cases are meant.
Reader Check
If you remove the “including” phrase, does the sentence still identify the same complete group, or does the phrase define the intended subset?
Recommendation
Use commas around an “including” phrase when it is nonrestrictive or supplementary; omit the comma when the phrase is essential to identifying the intended set.
Worked Example
Supplementary: “All participants, including the remote team, received the update.” Restrictive meaning may omit the comma when “including …” is needed to identify the intended cases.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Commas Q&A: comma before including — CMOS (opens in a new tab)Chicago Manual of Style · Direct style guidance on restrictive versus nonrestrictive including phrases