Bibliophemera

Here's an interesting post card with a scene from what looks like a German book shop at a military post during World War I. The handwritten letter on the reverse side is dated 21 May 1917 from Kanatlarci, Macedonia, which was occupied by the Germans during the Balkans Campaign of the Great War. The post card was not posted; there is neither a stamp nor a cancellation mark. Perhaps it was included with a letter or written and never sent. Regardless, the author undoubtedly never envisioned his note landing in Texas nearly a hundred years later. I can't make out the handwriting enough to take a stab at the German-to-English translation, but I did get Kanatlarci and the date, which told me World War I. A little research confirmed that quickly. The sign in the picture, plus the books in the window, confirm we're looking at some kind of book shop. The sign reads, Feld-Deutsche Buchhandlung , which translates, I believe, to Field German book shop . But what kind of book shop? I ...