Hyphens

For information about hyphenating specific technology words, see the A–Z word list. For information about hyphenating common words, see The American Heritage 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 The American Heritage 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 The American Heritage 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- exa- mega- pre- tera-
co- giga- micro- re- un-
cyber- kilo- non- sub-

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. For example, capitalize the first word if it's the first word of a sentence or heading.
Example
Customer-friendly content is brief, accurate, and to the point.

Capitalize the final part of a hyphenated compound word if it's the last word in a context that requires title capitalization, such as a book or song title.
Example
Bisson, Guillermo. The App E-Book. Redmond, WA: Lucerne Publishing, 2015.