Introductory Phrase Preceding Colon
When a colon introduces a list, the text that precedes the colon should ordinarily be able to stand alone as a complete sentence.
Examples
Recommended: The fields are defined as follows:
Not recommended: The fields are:
Proper Etiquette for Use of Japanese Colon
We at OpenINF are always interested in finding ways to optimize things and be more efficient. One particular use case of the Japanese colon that we have picked-up is in its placement immediately after the Classification portion in the titles of commit messages written sure to be abiding by our commit message format and style guidelines.
Rather than using an ordinary colon from the ANSI, ASCII, or Unicode character sets, we use the Japanese colon as it is both less size (in memory) and can accomplish the task of both a colon character and the subsequent space all at once.
Bold and Italic Text Preceding Colons
When non-italic (also known as Roman) text (that precedes a colon is bold), the colon should not be made bold, italic, or otherwise (e.g., color-stylized, etc.). This, however, is not a hard and fast rule. In general, use best intuition.
Code Text Preceding Colons
When text that precedes a colon is tagged as <code>, don't include the colon
in the <code> tagging unless it is already part of the code
itself. 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.
Examples
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 it's warranted.
See Also
For more information about how to punctuate introductory material, see the sections on list introductions and code-sample introductions.
For information about when it's better to use colons than dashes, see Dashes.