Had some fun reading through Apple’s Style Guide; made some revelations big and small. Did you know — at least by Apple’s standards — that website is one word? And that in the sentence “The temperature is –7 degrees on the mountain,” you need to use an en-dash to denote numbers below zero?

I didn’t. ¯\_(ツ)_/¯

dash (em) — Use the em dash (—) to set off a word or phrase that interrupts or changes the direction of a sentence or to set off a lengthy list that would otherwise make the syntax of a sentence confusing. Don’t overuse em dashes. If the text being set off doesn’t come at the end of the sentence, use an em dash both before it and after it.

• “See all your schedules—work, school, and social life—in one app.”

dash (en) — The en dash (–) is shorter than an em dash and longer than a hyphen. Use the en dash as follows:

• Numbers in a range: Use an en dash between numbers that represent the endpoints of a continuous range. For example, “bits 3–17”, “2003–2005.”

• Compound adjectives: Use an en dash between the elements of a compound adjective when one of those elements is itself two words.

  • “desktop interface–specific instructions”
  • “Grammy Award–winning producer”
  • “ex–Sun Studio tour guide”
• Minus sign: Use an en dash as a minus sign (except in code font, where you use a hyphen).

hyphenation — In general, hyphenate two words that precede and modify a noun as a unit. Follow this rule especially when:

• Confusion might result if the hyphen were omitted, as in parameter-list pointer or read-only memory.
• The second word is a past or present participle, as in binary-coded decimal or color-matching algorithm.
• The two modifiers are a number or a single letter and a noun or a participle, as in 32-bit color or D-shaped connector.

Follow these guidelines for specific cases:

• Units of measure: When you use a spelled-out unit of measure in a compound adjective, hyphenate the compound (27-inch screen). When you use an abbreviation or a metric unit of measure, including KB, MB, mm, and so on, don’t hyphenate (500 GB hard disk).
• Location compounds: Hyphenate compounds such as lower-left corner, top-right portion.

• Adverbs: Don’t hyphenate compounds with very or with adverbs that end in -ly.

• “very high speed”

• “recently completed project”

• Keyboard shortcuts using combination keystrokes: Use hyphens to signify that the first key or keys should be held down while the last key is pressed. (Don’t use hyphens if each key should be pressed and released separately.) Make sure you explain this convention on first use.

• “Control-Shift-N”
• “Esc N”

redownload — Don’t use; use download again.

road map — Two words.

U.S. — Use periods except in situations where the abbreviation appears close to other country name abbreviations that don’t use periods. Use the abbreviation as an adjective only; as a noun, spell out United States (except in trademark notices). To include the country name in a U.S.-based Apple address, use USA (no periods).

webpage — One word. A self-contained document that can be viewed on a website. A single website can contain many webpages. You connect to (or go to) a page; you’re then at that page. Text, graphics, and links, however, are on the page.

website — Refers to a collection of webpages stored in a particular location.