Wikipedia
Assistenzarzt (military)
Assitenzarzt (short: AArzt or AA) was a military rank in the Austrian-Hungary Common Army until 1918 and in German Reichswehr and Wehrmacht until 1945.
It describes a qualified or licensed surgeon or dentist comparable to 2nd lieutenant (de: Leutnant) or sub-lieutenant lieutenant (de: Leutant zur See) NATO-Rangcode OF1b in anglophone armed forces.