 FACT: Karl is mistakenly called a corporal. The Luftwaffe uniform  that he wears both in the US POW cage and while back in Germany has  the rank insignia of an "Obergefreiter", specifically three winged  emblems on the collar patches, plain shoulder straps and two  chevrons on his left sleeve. Also when the list is checked for his  name at the bridge the rank is written down as Gfr (gefreiter) The  ranks of Gefreiter, Obergefreiter and Stabsgefreiter (all which were  partially identified by chevrons on the sleeve) were not NCOs and  had no command authority over other soldiers. They were simply  grades of seniority and would be more equivalent to Private First  Class (PFC) in the US military. The German rank that is the closest  equivalent to Corporal is Unteroffizer. Also, Karl is wearing the  medical badge on his right sleeve; Luftwaffe enlisted medical  personnel wore the badge on the left sleeve, while Wehrmacht (army)  wore it on the right.