International maritime signal flags
International maritime signal flags are used to communicate with ships. They include alphabet (letter) flags, number flags, substitute flags and a Code answer pennant. Each letter flag is responsible for a letter (A-to-Z) and has its own ICS (International Code of Signals) meaning. This meaning depends on whether the flag is hoisted singly or with numeric complements. The “combination” meaning is described below the main one.
The total number of flags equals to 41.
The letter flags' size is 21 x 24 cm (8 x 9.5 inch)
The number and substitute flags' size is 29 x 14.5 cm (11.5 x 5.5 inch)