Vosges / France: WWI German Trench Position 30th Reserve Division Feldpost (Vintage PC 1916)

rare vintage world war i postcard titled "grabenstellung in den vogesen" showing a fortified german trench position in the voges mountains (alsace-lorraine front). the detailed scene illustrates soldiers at the parapet, a reinforced stone bunker, and wooden trench linings. published by phot. wipperling, elberfeld (no. 632).
the front features unique handwritten military identification notes in ink at the top edge from the sender, gefr. karl albert reuss, serving in the 3. abtg. res. feld. artl. regt. no. 239, as well as blue pencil markings.
the reverse is postally used as "feldpost" and addressed to reutlingen, germany, dated june 26, 1916. it features a very clear circular military cancellation stamp of the "k.d.feld-postexped. 30. reserve-div." from june 26, 1916. it also bears a distinct circular violet unit stamp reading "3. abtg. res. felda.-regt. 239 - i. mun.-kol. der iii. abtg. springer söhne, strassburg i. e.".
the postcard has extensive handwritten message in german script on the left side of the reverse.