Code letters
Encyclopedia
Code letters were a method of identifying ships before the introduction of modern navigation aids. Later, with the introduction of radio, code letters were also used as radio callsigns.
sponsored the Commercial Code of Signals for the Use of All Nations at Sea, which introduced four letter flag signal codes to identify individual ships. Circa 1870, the Comercial Code of Signals became the International Code of Signals
. By the 1860s, individual ships were being allocated code letters in the United States
and Europe
. From 1874, code letters were recorded in Lloyd's Register
as part of each individual vessels entry in the register. Generally, code letters allocated to a ship remained with that ship, although there are known cases where new code letters have been allocated following a change of port of registry or owner. Code Letters were sometimes reallocated once a ship had been struck from the register, but no two ships bore the same code letters at the same time. With the introduction of radio for communications, code letters were used also as radio callsigns.
History
In 1857, the United KingdomUnited Kingdom of Great Britain and Ireland
The United Kingdom of Great Britain and Ireland was the formal name of the United Kingdom during the period when what is now the Republic of Ireland formed a part of it....
sponsored the Commercial Code of Signals for the Use of All Nations at Sea, which introduced four letter flag signal codes to identify individual ships. Circa 1870, the Comercial Code of Signals became the International Code of Signals
International Code of Signals
The International Code of Signals is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp , flag semaphore, radiotelegraphy, and radiotelephony...
. By the 1860s, individual ships were being allocated code letters in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. From 1874, code letters were recorded in Lloyd's Register
Lloyd's Register
The Lloyd's Register Group is a maritime classification society and independent risk management organisation providing risk assessment and mitigation services and management systems certification. Historically, as Lloyd's Register of Shipping, it was a specifically maritime organisation...
as part of each individual vessels entry in the register. Generally, code letters allocated to a ship remained with that ship, although there are known cases where new code letters have been allocated following a change of port of registry or owner. Code Letters were sometimes reallocated once a ship had been struck from the register, but no two ships bore the same code letters at the same time. With the introduction of radio for communications, code letters were used also as radio callsigns.
Flags used
Code letters used the twenty-six flags that represent the letters of the alphabet. The ten flags that represent the digits 0 - 9 were not used.| Flag | Letter | Flag | Letter | Flag | Letter |
|---|---|---|---|---|---|
 |
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 |