Items in a breakdown should be parallel in construction — that is, all phrases or sentences. Phrase- and sentence-style lists can be mixed in a document, but it is always the choice of lead-in sentence or phrase that determines the punctuation that precedes the list and the options for punctuation and capitalization within the list. The one rule without an exception is that a sentence fragment introducing a list should not be followed by a colon. Here are the basic guidelines.
A colon is used after an introductory statement that contains the words “as follows” or “the following.” (See Sample.) A period is used after other statements introducing lists.
When the introduction is not a complete sentence and one or more of the items of the list are needed to complete it, no colon or dash should be used. (See Sample.)
When the breakdown items that follow an incomplete introductory sentence
are not complete sentences, the items begin with lowercase letters and end with no punctuation, regardless of whether the item itself contains commas or any other punctuation. (See Sample.)
contain one item in the list that is a complete sentence and therefore requires a period, then each item in the list, including phrases, should end with a period. Each breakdown item begins with a lowercase letter. (See Sample.)
When the breakdown items that follow a complete introductory sentence are complete sentences, each item should begin with an uppercase letter and end with a period. (See Sample.) The introductory sentence should always lead into the breakdowns following it if the breakdowns are incomplete sentences.
________________________________________________________
1 Section C9-2 was adapted from The Editorial Eye, Vol. 19, No. 4, April 1996.
