 A colon is also used between hours and minutes, titles and subtitles of books, city and publisher in bibliographies, in biblical citations between chapter and verse, and for salutations in business letters and other formal letter writing.The English word "colon" is from Latin ' ( '), itself from Ancient Greek (), meaning "limb", "member", or "portion".In Greek rhetoric and prosody, the term did not refer to punctuation but to the expression or passage itself.