Really liked this project by Harriet Russell testing the capabilities and, to some extent, sense of humour of the Royal Mail. She sent 130 envelopes each of which represented an address in some cryptic way, from crosswords (see below) to anagrams. Only 10 didn’t get through.
“Despite fears of a Royal Mail backlash, Russell found the system more than willing to play her game. The crossword edition was returned completed with the comment “Solved by the Glasgow Mail Centre”