- Front and back of semaphore alphabet card for Girl Guides
- Printed in Great Britain 1947
- 70 x 108mm (3 x 4½in)
The semaphore system uses two short poles with square flags, which a person holds in different positions to signal letters of the alphabet and numbers.
The person holds one pole in each hand, and extends each arm in one of eight possible directions. Except for in the rest position, the flags do not overlap.
The flags are coloured differently based on whether the signals are sent by sea or by land. At sea, the flags are coloured red and yellow, while on land, they are white and blue.