“Write the beginning of the sentence, then place a colon, and put the vertical list below that. Right?” Editors lose their minds when they hear writers simplify list punctuation in this way. It’s so much more nuanced than that. But sometimes, the writer is right about this. It’s a matter of style. (Note that several styles are used in this article by way of example. They do not reflect Copyediting’s house style.)
Defining a Vertical List
Quite simply, a vertical list is laid out vertically, rather than in line in running prose. The list can be bulleted or ordered with either numbers or letters (or a nested combination of all three).
Uses of a Vertical List
Vertical lists have many uses:
- They aid readability by breaking up blocks of prose.
- They help the reader skim the text.
- They can be used to cue the reader as to the content that follows (as when listing subheads or sections).
- They can help users navigate particularly long lists such as ingredients or data sets.
- They can highlight important content.
A numbered list can cue the reader to the order of steps, sections that follows, or the order of importance of a series of items. For example, this article covers
- defining a vertical list,
- uses of a vertical list,
- punctuating vertical lists, and
- going beyond punctuation.
Punctuating Vertical Lists
The Chicago Manual of Style (CMOS) lays out nuanced rules for punctuating vertical lists in six sections within Chapter 6. In the Publication Manual of the American Psychiatric Association (APA), check section 3.04, Seriation. But for the simplest rule, look to the Canadian Style (CS), which brings the introductory punctuation rule down to this: “The colon is generally used to introduce vertical lists.” [CS7.66] (Following a complex set of style rules has led some documents’ readers and reviewers to call the list style inconsistent.)
When you’re navigating new style, these are a few considerations you’ll want to take in for punctuating lists:
- When they should be used
- Whether each point should start with a capital letter
- When in the introduction introductory stem should end in punctuation, and what type of punctuation that is
- Whether each point should end in punctuation, and which type
- When bullets are preferred, and when letters or numbers should be used instead, or even if no punctuation will start each item
There is no style that doubles up leading punctuation—meaning that 1.) is not done.
Going Beyond Punctuation
One request that all style guides make when it comes to lists is that all items within a list use a parallel style. That is, the items are all set in the same tense, and use the same grammatical structure.