Hyphens

For information about hyphenating specific technology words, see the A–Z word list. For information about hyphenating common words, see Merriam-Webster Dictionary and The Chicago Manual of Style.

Predicate adjectives

Don't hyphenate a predicate adjective (an adjective that complements the subject of a sentence and follows a linking verb) unless the Microsoft Writing Style Guide specifically recommends it. Check the A–Z word list to find out.
Examples
The text is left aligned.
The camera is built in.
Many viruses are memory-resident.

Noun modifiers

In compound words that precede and modify a noun as a unit, don’t hyphenate:

• Very, when it precedes another modifier.
  Example
  Very fast test

• An adverb ending in -ly, such as completely, when it precedes another modifier. Check*Merriam-Webster Dictionary* if you're not sure whether the word ending in -ly is an adverb.
  Examples
  extremely stylized image
  highly graphical interface
  
  Note Use adverbs sparingly. They usually aren't necessary.

Hyphenate two or more words that precede and modify a noun as a unit if:

• Confusion might result without the hyphen.
  Examples
  built-in drive
  high-level-language compiler
  read-only memory
  lower-left corner
  floating-point decimal
  line-by-line scrolling
  scrolling line by line
  up-to-date information

• One of the words is a past or present participle (a verb form ending in -ed or -ing and used as an adjective or noun).
  Examples
  left-aligned text
  free-flowing form
  well-defined schema
  The schema is well defined.

• The modifier is a number or single letter plus a noun or participle.
  Examples
  two-sided arrow
  5-point star
  y-coordinate values

Suspended compound modifiers

• Don’t use suspended compound modifiers, such as left- and right-aligned text, unless space is limited. Instead, spell out the entire phrase.
  Example
  upper-right or lower-right corner

• If you use a suspended compound modifier, include a hyphen with both adjectives. The first hyphen is followed by a space.
  Example
  upper- or lower-right corner

• Don’t form suspended compound modifiers from one-word adjectives.
  Example
  uppercase and lowercase letters

Compound nouns

Hyphenate compound nouns when one of the words is abbreviated.
Examples
e-book
e-commerce

Exception email

Compound numerals and fractions

Hyphenate compound numerals and fractions.
Examples
a twenty-fifth anniversary
one-third of the page

En dashes in compound adjectives

Use an en dash (–) instead of a hyphen in a compound adjective when:

• The compound adjective includes an open compound.
  Examples
  Windows 10–compatible products
  dialog box–type options

• Two or more of the elements are made up of hyphenated compounds (a rare occurrence).

Prefixes

Avoid creating new words by adding prefixes to existing words. Rewrite to avoid creating a new word. If a word with a prefix is listed in Merriam-Webster Dictionary or the A–Z word list, it’s OK to use in Microsoft content.

In general, don’t include a hyphen after the following prefixes unless omitting the hyphen could confuse the reader.

• auto-
• co-
• cyber-
• exa-
• giga-
• kilo-
• mega-
• micro-
• non-
• pre-
• re-
• sub-
• tera-
• un-

Use a hyphen between a prefix and a stem word:

• If a confusing word results without the hyphen.
  Examples
  non-native
  pre-provisioned

• If the stem word begins with a capital letter.
  Example
  non-XML

A prefix affects a word, not a phrase. For example, instead of non-security related, use unrelated to security.

When adding a prefix to a stem word results in a double vowel and each vowel is pronounced, don’t use a hyphen.
Examples
reenter
cooperate

For more information about using prefixes, see The Chicago Manual of Style.

Capitalization in hyphenated compound words

Capitalize any part of a hyphenated compound word that would be capitalized if there were no hyphen. 

Examples

See also Capitalization