" I think there ought to be a regulation that the president could return a salute inasmuch as he is commander in chief and civilian clothes are his uniform.” “Well, if you did return a salute,” the general said, “I don’t think anyone would say anything to you about it.” The next time I got a salute, I saluted back. A big grin came over the marine’s face, and down came his hand. From then on, I always returned salutes. When George Bush followed me into the White House, I encouraged him to keep up the tradition. "
― Ronald Reagan , An American Life