How should bulleted lists be punctuated?
A vertical list is often confused with a vertical sentence. Firstly, decide whether the items are independent. If they are, then it’s a vertical list. If not, then it’s a vertical sentence.
For example, I might have a list of options, which have no particular order and are independent of each other. If they are both independent and non-sequential, you can format the list in three ways: a horizontal series, a bulleted vertical list, or a table. Only use a numbered list (1, 2, 3, etc.) if the items are sequential. Only label the list (a, b, c, etc. or i, ii, iii, etc.) if you need to reference items in the list from your text. The format of a numbered or labelled list is otherwise the same as a bulleted list—that is, as a vertical list. Finally, if the items are not independent (they are intrinsic to the meaning of the sentence), then format as a vertical sentence.
Okay, so that does sound complicated. But it will be become clearer with a few examples.
In general, use a horizontal series when there are three or fewer items or (if more than three) the items in the list are less important, such as a list of examples. In other words, don’t use a vertical list unless the information is important to the reader. A horizontal series is formatted as a sentence, with each item separated by a comma, and the final item preceded with “and” or “or”. For example, this series contains five items, but they aren’t important enough to emphasize as a bulleted list:
The database contains all standing data, including asset number, equipment type and class, load rating, installation date, date last serviced, and such.
Use a bulleted list for a series of four or more unordered, independent items. Introduce the list with a phrase ending with a colon. Capitalize the first word of all items. If any one item is a complete sentence (contains a verb), end all items with a period (full stop). Otherwise, there is no ending punctuation. In particular, do not end items with semicolons nor conjunctions “and” or “or”. For example:
At least one item is a complete sentence (end each with a period)
- Register a new trading right.
- Extend the period of an existing trading right.
- Cancel a current trading right.
- Transfer a trading right to another party.
None are sentences (no ending punctuation)
- Trading right
- Market schedule variation
- Registered capacity
This format is used to accentuate items in a horizontal series or to remove potential ambiguities in a sentence. A vertical sentence retains the capitalization and punctuation of the original, horizontal sentence. As such, items might have no ending punctuation or might end with commas or semicolons (rare), depending entirely on how the horizontal sentence would be punctuated. The phrases in a vertical sentence can be bulleted or labelled (for ease-of-reference). Only the last item takes an ending period. For example:
Ambiguous (as a horizontal sentence)
The retailer-of-last-resort (ROLR) provisions can be invoked in cases where the operator declares a state of force majeure and the market is administered or the market price is capped.
Meaning is clear (as a vertical sentence)
The retailer-of-last-resort (ROLR) provisions can be invoked in cases where
- the operator declares a state of force majeure and
- the market is administered or the market price is capped.
Conjunctions can be underlined (as above) at the writer’s discretion to assist the reader’s interpretation of each clause.
Remember, if the item is intrinsic to the meaning of the entire sentence, then format as a vertical sentence. Think of it as simply stretching the sentence down the page. Here’s another example of a vertical sentence with punctuation on each labelled phrase (preserved from how the sentence would be punctuated horizontally):
Network charges contained in a statement of charges can be adjusted to account for any error in or correction of or substitution of
(a) metering data,
(b) estimates of consumption for periods after the last meter reading,
(c) network tariffs, or
(d) any other amount or factor that affects the calculation of the network charges.
Style Guide: formatting lists
October 8, 2015 / Tim McAuley / 0