1. Indicate, by three spaced points, omission of words or sentences within quoted matter: Equipped by education to rule in the nineteenth century, … he lived and reigned in Russia in the twentieth century.—Robert K. Massie
  2. Indicate, by four spaced points, omission of words at the end of a sentence: The timidity of bureaucrats when it comes to dealing with … abuses is easy to explain. …—New York
  3. Indicate, when extended the length of a line, omission of one or more lines of poetry:
    Roll on, thou deep and dark blue ocean—roll!
    . . . . . . . . . . . . . . . . . . . . .
    Man marks the earth with ruin—his control
    Stops with the shore.—Lord Byron
  4. Are sometimes used as a device, as for example, in advertising copy:
    To help you Move and Grow
       with the Rigors of
    Business in the 1980s …
       and Beyond.—Journal of Business Strategy

See also: The Dash and the Hyphen and the Ellipsis.