Rules of Punctuation (The Hyphen)

The Hyphen

(a) When attaching a prefix (e.g. self-explanatory, anti-hero) and especially when confusion might result as with "re-sign" and "re-form"

(b) When forming a compound word from two or more other words:

e.g. son-in-law, a half-eaten biscuit, and a couldn't-care-less attitude, red-hot-smoking-jacket.

Distinguish "fifty-odd people" from fifty odd people.