@whiteline just a made up silly way like "prisoner of war post" which is sometimes also used, e.g. by so called Reich citizens, ultra-right demented boomers.
@kaia It's faster to just deliver the postcards when you're doing the rounds to deliver the parcels/mail already then to take them back to the post office, check that they're not a valid postcard (you don't want to destroy valid postcards) and put em through a shredder.
@kaia "it would cost more to destroy them" smirks the postal service worker, knowing that if he destroyed them they would cease to be sent and cease to cost anything to destroy, but that if he delivers them they will continue to come and continue to cost money to deliver. Anything to ensure continued use of the post. Spam is fine too. Even delivering the mail of ten generations of prior residents at your address is fine.
@kaia we should just accept the private land of Reichsbürger as foreign soil, cut off all utilities and post a single border guard at their gate to deny them entry into germany