A colon indicates that closely-related information follows.
Introductory phrase preceding colon
When a colon introduces a list, the text that precedes the colon must be able to stand alone as a complete sentence.
Recommended: The fields are defined as follows:
Not recommended: The fields are:
Bold text preceding colon
When non-italic (roman) text that precedes a colon is bold, don't make the colon bold too.
Code text preceding colon
When text that precedes a colon is tagged as
<code>, don't include the colon
<code> tagging unless it is part of the code. For more information
about formatting code, see
Some specific items to put
in code font.
Colons within sentences
In general, the first word in the text that follows a colon should be in lowercase. For exceptions, see Capitalization and colons.
Recommended: Tone: concise, conversational, friendly, respectful
Recommended: When you add or update content to an existing project, remember to take these steps: review the style guide, use checklists, enlist a fellow writer or an editor to copyedit your work, and request a developmental edit if you feel that it's warranted.
For information about when it's better to use colons than dashes, see Dashes.