Semicolon Before Explanatory Words Introducing a List
The Semicolon
Rulebase Summary
Use a semicolon before words that introduce an explanation, enumeration, or list — such as namely, that is, that is to say, for example, e.g., i.e., as, or to wit. A comma follows the explanatory word. The material after the explanatory expression does not need to be an independent clause. However, if the explanation after the introductory word is only a single word or very short phrase (not a list), use commas around the explanatory expression instead of a semicolon.
Examples
A. He suffered multiple injuries, namely, a broken arm, fractured ribs, and a concussion.
A. He suffered multiple injuries; namely, a broken arm, fractured ribs, and a concussion.
Semicolon before 'namely' introducing a list.
A. She had one concern, that is, whether the lease had been properly executed.
A. She had one concern; that is, whether the lease had been properly executed.
Semicolon before 'that is' when it introduces an explanation.
Style Guide References (2)
Morson's
BGGP