By MJ Malleck// Update: Mystery Solved Thanks to an anonymous friend, the mystery of the secret code is revealed. Here's what the postcard writer wrote: "Well, what do you know all the way from New Orleans and in semaphore. We are fine and hope you are too." The key to unlocking the code came from his knowledge that, in English, the only double letters at the end of words are ll or ss. Seemed likely that the 3-letter word (sixth word in) must be ill or all. The symbol used for the second letter in the first word is used twice as much as any other symbol, so almost certainly an E, the most common English letter. (My friend plays Scrabble too.) Making the first word, Well. After an hour, he had it. For those who don't know what semaphore means (I did not) it is a method of visual signaling, using flags or lights. The Chappe-Code I mention in the original post, was an kind of signaling using towers with moveable arms. The Boy Scouts used to teach the two-flag system
Sharing postcards from the '60s and forward, bought at a garage sale, in Ontario Canada.