Courier's Code

The Courier's Code is a secret way of messaging used by the Diplomatic Service and Ranger Corps.
The code arranges the 24 letters of the alphabet into rows and columns. The format of the message is set in a square outline.
The sender would move a light to a corner of the square before flashing the light. The letter’s row corresponds to which corner the light is in, and the column corresponds to the number of times it flashes.
Note: the left and right is according to the receiver. The sender needs to flip it for themselves. (i.e. left corner becomes their right corner)
W and Z are substituted by V and S if necessary.

Letters and Numbers in the Couriers Code by the Diplomatic Corps Courier Service

Couriers Code Placement Chart by the Diplomatic Corps Courier Service

Row numbers 1 – 4 are shown in the corners; Column numbers are shown in the middle.

The structure of the Courier's Code by the Diplomatic Corps Courier Service

Example
For the letter I, the sender would put the light in the top right-hand corner of the square, and then flash three times.

Example: the letter I by the Diplomatic Corps Courier Service

Used By
Diplomatic Corps
Ranger Corps