Other Punctuation

In addition to the most commonly-used forms of punctuation (i.e. commas, periods, and question marks), good writing requires the use of other punctuation marks: colon, quotation marks, dash, parentheses, square brackets, slash, ellipsis. 

Colon

The colon calls attention to the words that follow it. It introduces a series, explanation, appositive, or long quotation. In any case, the colon must be preceded by an independent clause.

Series:
Our cat George always needed to take certain things on trips: her security blanket, a rubber chicken, and a picture of her mommy.

Appositive:
(An appositive is a noun or noun phrase that renames another noun in the sentence.)
George induces two reactions in the people who come to visit: violent sneezing fits and baby babble. 

Quotation:
But remember what Mother said when George got on the countertop last summer: "Next time that cat does something stupid like that I'm goin' to fix my famous cat soufflé." 

Explanation:
Our cat George is a Sherman tank: She is big, round, solid, and always knocking things over.
or
Our cat George is a Sherman tank: she is big, round, solid, and always knocking things over.

(When followed by an independent clause, the clause following a colon may begin with either a lowercase or capital letter.) 

Long Quotation:
(Generally, this will take the form of a block quotation). 
See Document Citation for MLA and APA guidelines.In the introduction to the book mother is currently writing, The International Encyclopedia of Mixed Breed Cats, she states: 

Cats of mixed breeds are brilliant stars in the Universal Mother's corset. She has generally determined that mixed breed cats should live longer than pure breeds, and also she blesses them and holds them in places of honor because they are more accepting of litter boxes and are more independent. In general, you should love your mixed breed cat as you would a priest, a nun, or a Buddhist monk.

Quotation Marks

Quotation marks are used to indicate words or phrases that are not your own, to signify a speaker's words in dialogue, or to indicate words or phrases which you feel should be set off for emphasis. Quotation marks are also used with words or phrases that are to be read as subjects or objects in the sentence. 

Quotation:
When the priest asked what Mother thought of our cat, she said, "George is a wonderful cat." 

Dialogue:
"Oh! You foul cat!" Mother shrieked, "What in the heck are you doing in the trash can and making such a mess?"
"Meow," the only reply George would offer, did not satisfy her.
Mother exclaimed, "Oh! So now you're going to play dumb and innocent. I know you. You're a cat! You knew what you were getting into."
"Meow," again George replied. 

Emphasis:
Mother thought George once belonged to James Brown because George had "da funk."

(Note: when possible, it is preferable to use italics in this instance.) 

Entity: 
The name "George" was chosen for our cat because she is so regal.

Dash

The dash is used to signify a shift in thought or tone, an unfinished thought, or hesitation in dialogue. Also, it can be used in place of commas or parentheses to emphasize appositives and modifiers, or to set off a series or explanation. 

Shift in thought or tone:
George seems to sense--but does she really know?--that she is going to the vet every time we put her in the car. 

Hesitation in dialogue: 
"It seems George had too much catnip, and she--" I paused and scratched my head with concern.
"She what?" Mother demanded.
"Well, she--oh, dear. She ate one of your dishtowels." 

Unfinished thought:
If Mother got her hands on George--I am afraid to think of what she will do to her. 

Appositives:
The things George values most in life--catnip, sleep, food, and more food--are always easy to come by at our house. 

Modifiers:
Though George's litter box is close by--only inches from her food and bed--she still insists on going outside for privacy. 

Series:
At the vet, George encountered a number of dogs--a grimy German shepherd, a sheepdog named Linda, a pomeranian with a mowhawk, and a poodle with a tail fetish.

Explanation:
George is lucky she made it out of the vet's office alive--the poodle nearly bit off her tail. 

Parentheses

Parentheses are used to enclose supplemental information, such as facts, digressions, explanations, and examples. 

Facts:
George is a calico (thus female) with big blotches of orange and gray fur spattering down her legs and white-tipped tail. 

Digressions:
George hates my uncle Lou (who once pulled her tail too hard) and leers at him every time he enters the house. 

Explanation:
George sleeps in the front window (the sunlight is brightest there) every day from noon until dinnertime. 

Examples:
George eats only certain flavors of cat treats (shrimp, chicken, and beef) and turns up her nose at the rest. 

Square Brackets

Brackets are used only within quotations. They indicate your own comment or change made within someone else's quote. 

My mother said, "George is always getting in my way. Soon [she will] be banished from my house."

Slash

The slash is used in poetry to separate lines that are run together by the text. It is also used to separate different options in all kinds of writing. 

Poetry:
George loves to listen to me reading poetry. Her favorite line is from T.R. Hummer's poem "Compound Light": "Watch the two of them now, how anonymous they are / As the sun detonates through the fogbank and the cruiser stutters." 

Options:
What time George is fed is not a now/later situation. It is always now. 

Ellipsis

The ellipsis is most often used to indicate omissions from a quotation.

In the introduction to the third chapter of Mother's book, she says of mixed breed cats that they are, "prone to not get chicken pox . . . because their gene pool is considerably more diverse."

"George is the coolest cat I've ever met . . ." -- Old Aunt Lizzy