Today's flag is: Zulu
As a letter, that is the letter Z.
As a message, it means: I require a tug.
When made by fishing vessels operating in close proximity on the fishing grounds it means: “I am shooting nets”.
boof (OP) double-posted this 1 year ago, 10 hours later, 1 day after the original post[^][v]#1,334,265
When the flag is presented with flags representing four numerals, then the meaning is:
GMT (the first two denote hours and the rest minutes).
When the flag is presented with a flag representing one numeral, then the meaning is:
To call or address shore visual stations (numeral to be approved by local port authority).
boof (OP) triple-posted this 1 year ago, 1 day later, 2 days after the original post[^][v]#1,334,489
The declassified NATO information for flag Zulu:
indication: COMMUNICATION GUARD
normally displayed: Where best seen (not underway).
WHILE FLYING: meaning: I have communication guard duty.