This declaration corresponds to the flushright environment. This declaration can be used inside an environment such as quote or in a parbox.
Unlike the flushright environment, the \raggedleft command does not start a new paragraph; it simply changes how LaTeX formats paragraph units. To affect a paragraph unit's format, the scope of the declaration must contain the blank line or \end command (of an environment like quote) that ends the paragraph unit.
See also: Environments, flushright,