Signal flags: the International Code of Signals
Every flag of the code has its own page with the meaning, pronunciation, Morse sign and real-life use. Search by code, name or meaning (e.g. "diver", "pilot", "tug").
The search runs in your browser. Without JavaScript, use the flag grid below or the cheat sheet.
Interactive mast Type a code or click flags and watch the hoist come together on the mast. Flags quiz 10 questions: recognise the flag or match the meaning. No sign-up. Cheat sheet: single-letter signals Every meaning A to Z in one table, for a quick revision. Code book Works both ways: type a code and get the meaning, or describe the situation and find the signal.
Letters A to Z
A 
B 
C 
D 
E 
F 
G 
H 
I 
J 
K 
L 
M 
N 
O 
P 
Q 
R 
S 
T 
U 
V 
W 
X 
Y 
Z Numeral pennants 0 to 9
0 
1 
2 
3 
4 
5 
6 
7 
8 
9 Answering pennant and substitutes
AP 
First substitute 
Second substitute 
Third substitute 
Fourth substitute The single-letter meanings are quoted 1:1 from Pub 102 International Code of Signals (a US government publication, public domain); the plain-English explanations are our own editorial. Flag graphics: the signal-flag-images project (Unlicense, public domain).