The strange supplemental postal service "Zustellungsurkunde" (first introduced in frame 5, page 3) has been a bane to this exhibit. American judges simply don't understand the service or appreciate the scarcity of the documents. Perhaps the best appreciation of the 4 documents shown in this exhibit was at Pacific 97, judged by international judges.
Zustellungsurkunde is first and foremost, a service. It is also the accepted name (by European collectors) for the return document showing the service had been preformed. I guess a perfect description of these documents would be "document returned to indicate Zustellungsurkunde had been properly preformed by the postal official who delivered the attached letter". But what the heck, here in the United States, we have "Air Mail" Letters that never flew a foot by themselves and "C.O.D." packages that never collected a cent on their own!
Zustellungsurkunde basically turned the post man into a process server. In Germany, a return receipt for registered mail was not legal proof of delivery for some reason. The "Zustellungsurkunde" document, returned to the sender, was acceptable as legal proof. It listed what was delivered, who received it, where, when and other details. It was signed by the postal employee who did the work. Officials, Clergy and Notaries received a reduced (20 Pfennig) fee charge when they used the service, the public paid 30 Pfennig.
I found this cover and will try to work it into the material on frame 5, page 3 to better explain the service. The key on this cover is in the lower left corner " Hierbie ein Formular zur....". This mail is an original letter sent, requesting the Zustellungsurkunde service. If you look closely, you can see the pin holes on the left side of the envelope where the "Zustellungsurkunde" document was attached when it was sent.
And, of course, if anyone has any suggestions, I am more than willing to consider them.