Colon (punctuation)

The colon ( : ) is a punctuation mark consisting of two equally sized dots centered on the same vertical line. A colon precedes an explanation, or an enumeration, or list. A colon is also used with ratios, titles and subtitles of books, city and publisher in bibliographies, Biblical citations between chapter and verse, and—in American English—to separate hours and minutes, for business letter salutations and in formal letter writing.