Lawyers love bullets, letters, or numbers in a vertical list. I see those lists capitalized and not, with periods and not, with commas and not. So what is the correct way to show a vertical list? You can use bullets, letters, or numbers – any of those is correct and a matter of personal style preference.
You should capitalize the first word of the list if it is a complete sentence. If it is not a complete sentence, you can choose whether or not to capitalize the first word, but if you make the choice to always capitalize the first word, you won’t have to try to decide if it is a complete sentence or not. Capitalizing every time has my vote!
As for whether or not to use a period, if each entry on the list is grammatically complete, or if the list completes the introductory sentence, use a period, exclamation point, or question mark as appropriate. If it is a single word list entry or a sentence fragment, you can choose whether or not to use terminal punctuation.
For example:
Can you give me instructions for:
- Changing the oil in my car.
- Finding the proper air pressure for my car tires.
- Filling the windshield wiper fluid.
Can you give me instructions for (1) changing the oil in my car, (2) finding the proper air pressure for my car tires, and (3) filling the windshield wiper fluid.
No capitals, the use of commas, and the word and are all appropriate in this case.
When your list is more like a shopping list or an inventory or if the introductory sentence is complete, do not use commas or periods.
My favorite electronic devices are:
- iPhone
- iPad
- Laptop
The other issue I frequently see with these types of lists is parallel treatment. In my car example above, the words changing, finding, and filing are parallel. This is something to check when proofreading so that your list does NOT read:
Can you give me instructions for:
- Changing the oil in my car.
- The proper air pressure for my car tires.
- Windshield wiper fluid filling.
While each of those list entries is correct by itself, they are not parallel. Lists are useful and probably necessary, as long as they are set up correctly.