The Stars & Stripes article that appears on the right was published just ten days before the war came to a close and it made clear that the most noticeable changes to made concerning the POW uniforms will be the far larger "PW" designations that appear on both trouser and chemise.
Pictured above you can see two German prisoners of war under guard while they do farm work and, as the article noted, it is difficult to see any indication as to their status. The Photograph was found in the book America's Munitions, 1917-1918 (1919).
Click here to read about the W.W. II Canadian POWs who collaborated with the Nazis.