I forgot to mention this immediately after, but last weekend I was at a SFF con and wearing my Correspondence t-shirt. I had one person try to decipher it! Explained to them and another what it was referring to, and possibly sold some people on Sunless Sea by mentioning that Amal El-Mohtar had written an island for it (since Amal was at the con).
Anyone else had fun conversations about their FL swag?