HBR Guide to Better Business Writing (HBR Guide Series)

Appendix C

A Dozen Punctuation Rules You Absolutely Need to Know

1. Hyphenate your phrasal adjectives.

   A small-business incentive is different from a small business incentive. A limited-liability clause is different from a limited liability clause. When two or more words as a unit modify a noun, they must be hyphenated (unless certain exceptions apply). So a hotel’s door sign advising the staff not to disturb the guests would be a do-not-disturb sign. A company that is 25 years old is a 25-year-old company.

   There are some exceptions: (1) Don’t hyphenate simple phrases formed by an -ly adverb and a past-participial adjective <a greatly exaggerated claim>. (2) Don’t hyphenate phrases formed with proper nouns <New Zealand exports> or foreign words ...