One of my current projects is reproducing stamps for wartime Wehrmacht travel documents. This service stamp was used to certify two typed notations on the reverse of a Kriegsurlaubsschein. While one would expect a stamp of a military unit or Kommandantur, or perhaps a generic type Feldpost number stamp, this stamp reads simply "Dienststelle"- duty station. I am not sure why there is no other information on this stamp, perhaps it was for security reasons, but in any case this is certainly the most generic service seal I have ever seen, and could theoretically have been used for almost any purpose. If I had not seen this myself I would have never believed that it was real and used during the period. I have copied it exactly.