7 Writing Style

Punctuation

Punctuation matters. The omission of a single comma can reverse the meaning of a sentence. Consider these two sentences:

No, price too high.
No price too high.

The following provides some guidelines on using the common marks of punctuation. Those marked with an asterisk* are also discussed in more detail in the Writing Styleguide.

.	Period – used to end a sentence or to indicate an abbreviation.

,	*Comma – used to link complete thoughts together, enclose parenthetic thoughts, or separate off introductory phrases.

;	*Semicolon – used to separate two independent clauses not joined by a conjunction. Often thought of as a soft period. Avoid—use periods instead.

:	*Colon – used at the end of a phrase introducing a bullet or numbered list.

’	*Apostrophe – used to form possessives of nouns, such as “children’s,” or to show the omission of letters, such as “don’t.”

“ ”	*Quotation marks – used to indicate a quotation from a person or publication.

‘ ’	*Single quotation marks – used to indicate a quotation within a quotation, or to indicate a colloquialism. Neither use is common in manuals.

( )	*Parentheses – used to set off remarks that explain or comment on the sentence. Avoid in manuals.

[ ]	*Brackets – used to indicate your own words within a quotation, or quotations within quotations. Seldom used in manuals.

…	*Ellipses – used to indicate an omission within a quotation. Seldom used in manuals.

—	*Em dash – used to enclose or set off parenthetic expressions or abrupt changes in thought. Don’t use hyphens instead, and don’t put spaces on either side.

–	*En dash– used to indicate continuing or inclusive numbers, such as dates, times, or reference numbers. Don’t use hyphens instead, and don’t put spaces on either side.

-	*Hyphen – used in hyphenated words, such as “co-worker,” or to create compound modifiers, such as “one-day course.”

?	Question mark – used to indicate a question. Use sparingly.

!	Exclamation mark – used to emphasize a statement. Avoid in manuals.

&	Ampersand – symbol for “and.” Spell out instead.

/	*Slash – used to indicate an and/or situation. Avoid by stating whether one or both possibilities apply.