Attached is small notice that appeared in the Doughboy newspaper, THE STARS & STRIPES; it named the three American officers who served "over there" long enough to be granted the adornment of a fourth overseas chevron. Each gold wire chevron, worn on the lower left cuff (see the officer's cuff pictured above), represented a single six month period served in theater; the vast majority of A.E.F. uniforms had anywhere between one and three sewn in place.
Another article about over-seas chevrons may be read here...