Mary, Queen of Scots prison letters finally decoded
Am I dense, or is this article and <a href="https://arstechnica.com/science/2023/02/lost-and-found-code-breakers-decipher-50-letters-of-mary-queen-of-scots/" rel="nofollow">https://arstechnica.com/science/2023/02/lost-and-found-code-...</a> (mentioned by another commenter) almost completely void of details about the cipher? I'm most interested in how Mary was encrypting these letters, but apart from an image or two in the article mentioned above, and this quote "The documents contained only graphical symbols (more than 150,000 in total)", there's nothing.