The fewer hyphens the better; use them only when not using them causes confusion.
Use a hyphen to separate noninclusive numbers, such as telephone numbers: 517-355-1855, 1-800-942-7866 (1-800-WHARTON).
Use a hyphen in compound modifiers. See adjectives, phrasal
But when a modifier that would be hyphenated before a noun occurs instead after a form of the verb to be, the hyphen usually must be retained to avoid confusion: The man is well-known. The woman is quick-witted. The children are soft-spoken.
Do not use a hyphen to designate dual heritage: Italian American, Mexican American, French Canadian, Latin American.
Avoid duplicated vowels, tripled consonants: Examples: anti-intellectual, pre-empt, shell-like.
Most words formed with prefixes (e.g., midcareer, multidisciplinary, metadata) are not hyphenated. However, a hyphen is used when the prefix precedes a proper noun (mid-July) or to avoid double i’s (multi-institutional), double a’s (meta-analysis) and other combinations of letters or syllables that might cause misreading (re-cover versus recover).
Words formed with the suffix “wide” do not include a hyphen (e.g., campuswide) unless they have more than two syllables (e.g., university-wide) or include a proper noun (Lansing-wide).