Above all, treat lists consistently within a document.
Number items in a vertical list only when the order of items matters. If any or all of the items in the list are complete sentences, punctuate all items in the list with periods:
If you are the first to arrive at the office in the morning:
- Turn off the security alarm.
- Turn on the copy machine.
- If none of the items are complete sentences but the list completes a sentence, follow each item with a comma and end the list with a period.
Otherwise, use bullets or another typographical symbol. If the items in the list combine to create a complete sentence, separate each item with a comma and include a conjunction before the final item:
When you begin speaking to a large group, you can expect the following:
- to be extremely nervous
- the stage lighting to be blinding,
- your throat to start contacting, and
- your hands to shake from pure terror.
If none of the items are complete sentences and the list does not complete a sentence, do not include punctuation at the end of each item, including the final one:
This boat has several attractive features:
- a mast
- an engine
- a galley
- a hull that doesn’t leak
Lists in Text
Use semicolons to separate long items that occur in a list:
- Lynette is the world’s leading expert on the natural science of the northeastern section of Oregon; the history of the cave dwellers on the island of Santa Catalina; the speed and handling capacity of 12-meter sailboats; and the best and worst restaurants, hotels, and beaches of the central California coast.
Use semicolons to separate items that contain commas:
- The new professors introduced at the assembly were from Victoria, British Columbia, Canada; linkoping, Sweden; Cheyenne, Wyoming; Sydney, New South Wales, Australia; and Milan, Italy.
Place parentheses around numbers or letters listing items in a series:
- Jack insisted that only Joe DiMaggio could be compared to Willie Mays because both could (1) hit with power, (2) field brilliantly, (3) run the bases exceptionally well, and (4) hit in the clutch.