Capitalization

The three main styles of capitalization used online and in email are sentence case (The story of my life), title case (The Story of My Life), and all uppercase (THE STORY OF MY LIFE). All uppercase is commonly called all caps.

Whichever style of capitalization you choose for your site, perhaps the most important consideration is to use the style correctly and consistently across the site, to ensure a coherent, deliberate look and feel. You may even decide to use more than one style of capitalization. For instance, you could use one style for article titles, one for subheadings within articles, and one for tab labels. This decision can work beautifully as long as each type of heading is consistently capitalized in one style.

For more information on writing and choosing a style for headlines and subheadings, see “Headings.” For more information on the different types of site-navigation text, see Write Clear User-Interface Text.

Capitalize the text as if it were a sentence:

• Capitalize the first word and all other words normally capitalized (such as proper nouns).
• If the first word is a proper noun that begins with a lowercase letter (like iPhone), try to reorder the title or sentence so that you can capitalize the name as the company usually does. If reordering is impossible, capitalize the first letter and any other letter the company usually capitalizes: IPhone.

Examples
Tony Award winner takes Emmy, eyes Oscar
Sales of iPod soar
IPod sales soar (Acceptable only if “Sales of iPod soar” won’t fit)

This style has more rules than sentence case:

• Capitalize the first and last words, regardless of the length of the word or the part of speech.
• For the words in between, capitalize all nouns, verbs, adjectives, adverbs, and pronouns, regardless of the length of the word. Capitalize prepositions of four or more letters (like over, from, and with). And capitalize conjunctions of four or more letters (like unless and than), as well as if and how and why.
• Do not capitalize:
  • Articles (a, an, and the)
  • Prepositions of three or fewer letters (such as of, in, and for)
  • Most conjunctions of three or fewer letters (like as, and, or, and but)

Examples
“Don’t Fence Me In”
“Walk With Me in Moonlight”
“Turn Off the Lights, I’m Home” (“Off” is an adverb here, part of the phrasal verb “turn off.”)
“She Took the Deal off the Table” (Here, “off” is a preposition.)
“What If I Do, What If She Won’t”
“The Least She Could Do Is Cry”

• If the first word is a proper noun that begins with a lowercase letter (like iPhone), try to reorder the title so that you can capitalize the name as the company usually does. If reordering is impossible, capitalize the first letter and any other letter the company usually capitalizes (IPhone). If such a noun falls elsewhere in the title, use the company’s capitalization style (iPhone).

Examples
Sales of iPod Soar
IPod Sales Soar (Acceptable only if “Sales of iPod Soar” won’t fit)

Hyphenated compounds in title case

If a hyphenated compound appears in title-style capitalization, capitalize the first word, and capitalize all subsequent words in the compound except for articles (a, an, and the), prepositions of three or fewer letters (like to and of), and coordinating conjunctions (for, and, nor, but, or, yet, and so). Ask yourself: If this word weren’t in a hyphenated compound, would I capitalize it? If the answer is yes, capitalize it as part of the hyphenated compound, too.

Examples
The Big Spender’s Budget How-To (Capitalize any word, even “to,” at the beginning or end of a title.)
Author of How-to Book on Bee-Keeping Prone to Anaphylaxis
Governor Slams E-Book About Her Re-Election Campaign
Consumers Prefer Eco-Friendly and Cheap Products
Two-Thirds Vote Needed to Fund Research Into Blue-Green Algae Biofuel
Profits Double on Word-of-Mouth Sales
Audiences Love His Man-About-Town Sophistication
Open Your Own eBay-Based Boutique

This style (commonly called all caps) calls for every letter of every word to be capitalized. In general, avoid this style. It is often difficult to read, it can unintentionally convey alarm, and some people regard it as shouting.

Avoid using all uppercase for emphasis. Instead, use boldface, italics, or a graphic design. And remember that linked text already stands out: Links tend to catch the eye of a scanning reader.

Examples
Before
DOW UP 100 AT CLOSE
After
Dow Up 100 at Close

Before
Register TODAY and receive a FREE GIFT.
After
Register today and receive a free gift.

If it is not overused, all uppercase can be appropriate in warning messages, where a single word set in capital letters can alert readers to a situation requiring attention (IMPORTANT: Do not click the Back button), and in plain-text emails, where boldface and other devices for emphasizing headings can’t be used.