Yes - Kind of -- When at sea (56-60) if I remember correctly we had a book of International Signal codes covering 1 to 4 flag hoists. Many years ago after swallowing the hook, but still a boat owner, I looked for a similar book, and found one but only with the standard one flag hoists (indelibly printed in memory) and two flag hoists. I suspect I am probably one of the few private boat owners who can boast possession of a complete set of International Code flags.
I also make a point of dipping my Ensign to any passing armed Naval vessel. (Just to see them send some poor bloke scurrying down to their taffrail to dip theirs.