Answer: Prize puzzle 11 cents and 15 cents

1. A number of values ​​of the series of postage stamps from earlier issues became redundant because the values ​​no longer corresponded to the rates applicable in 1924. These surplus postage stamps were not destroyed but overprinted with a different value so that they could still be used for franking. Postage due stamps were also required, and some of the surplus stamps were overprinted to make them suitable as postage due stamps. 2. When the print runs with the overprinted postage due stamps were delivered, the numbers of the 11 cent and 15 cent stamps proved to be so small that the PTT decided NOT to use them via the post offices to prevent speculation. Therefore, they were used exclusively internally in 1924 and 1925, meaning within the PTT itself. It was the departments at the post offices in Amsterdam, The Hague, and Rotterdam that handled postal parcels that had been returned or needed to be forwarded. Settlement was done on a form stating the amount due. This amount was 'settled' by means of postage due stamps. Ordinary postage due stamps, but also overprint stamps. In this case, the 11-cent and 15-cent values ​​were NOT for a specific rate. They were affixed until the amount due was reached. Because these postage due stamps were affixed ONLY by postal officials in the relevant departments, and were not sold at the counters, they did not end up in the hands of collectors. Only very few overprint stamps have remained uncancelled. 3. Because the overprinted stamps only 'came onto the market' via State Auctions in 1925, after they were no longer in use, the 11-cent and 15-cent postage due stamps were initially boycotted. Only much later did they find their own place in albums and catalogues.