How it works
This international code flags quiz shows the flags ships spell and signal with: 26 letter flags, ten number pennants, three substitutes and the answering pennant. Name each one, then learn what a letter flag says when it flies alone.
Read the full guide
Two sets
Letters and numbers shows a flag and asks which letter or number it stands for. What it means alone names the letter and asks for its message, such as flag O for man overboard. Tap a choice and the answer shows at once.
A round, the list and a sheet
A round is ten questions. The list under the quiz gives every answer. After a round, Print lists its ten questions and prints the flags, with a key on a tick.
Where the flags come from
Each flag was drawn for this site from the plate in the International Code of Signals. Each meaning is the code book's own, in shorter words.
- The whole set uses five colors: red, yellow, blue, black and white.
- Only two letter flags have a notch cut into the outer edge: A and B.
Questions and answers
How many flags are in the International Code of Signals?
Forty. A full set is twenty-six letter flags, ten number pennants, three substitutes and the answering pennant, which is also called the code pennant.
What does the yellow Q flag mean?
Flown alone, the plain yellow flag Q says: my vessel is healthy and I request free pratique. Pratique is the clearance a ship is given to enter a port once its health rules are met.
Which signal flag means man overboard?
Flag O, Oscar. It is cut from corner to corner into two triangles, a yellow one against the pole and a red one at the outer edge.
What is a substitute flag for?
A substitute repeats a flag already in the same hoist, so a ship with one set of flags can still signal a doubled letter or digit. The first substitute repeats the top flag, the second the second, the third the third.
Are the flag names the same as the NATO alphabet?
Yes. The code book spells the letters Alfa, Bravo, Charlie and on to Zulu, the same code words as the NATO spelling alphabet, with Alfa and Juliett spelled that way.