When the lamps are placed horizontally, they are read from the sender's right to his left, and consequently from the receiver's left to his right.
When the letters of the alphabet are to be used to indicate the meaning set opposite them in the following tabulation, the upper light of the display is pulsated. This is effected by means of a special pulsating key. Special signification is not given "I" and "T," they being represented by a single lamp.
-----------+---------------------------------------- Steady | Upper light pulsated. display. | -----------+---------------------------------------- A | Cipher "A" use. B | 0 (naught). C | Repeat (following rule for conventional | signals under wigwag code). D | Telegraphic dictionary use. E | Error. F | 4. G | 6. H | Compass signals use. I | J | 5. K | Negative. L | Geographical list use. M | 9. N | Cipher "B" use. O | Cipher "C" use. P | Affirmative. Q | Interrogatory. R | International code use. S | General signals use. T | U | Navy list use. V | 7. W | Annulling. X | Numerals. Y | Vessels' number use. Z | 2. Letters | 3. Code call | 8. Interval | Boat signals use. -----------+----------------------------------------
Before numerals are made, the distinctive signal for "numerals" "X" is shown and the upper light is pulsated, which serves still further to distinguish them from letters. The resumption of letters after using numerals will be indicated by the upper light being no longer pulsated, but the display "letters" ("3") will be turned on as an additional indication.
The acknowledgment of the correct receipt of a message will be indicated by the letter "R." If the message has not been fully received, or if it is not understood, indication thereof will be made by signaling the letter "G."
Letters of the army and navy alphabet may be represented at night by Coston lights, port fires, or other colored pyrotechnical lights by displaying the "red" for one and the "white" for two.
In using the Morse alphabet the "red" represents the dot and the "white" the dash.
Coston signals and other similar lights are best suited for preconcerted signals.
The navy signal book is used, to which the following explanation refers:
The letter R stands for red and the letter G for green, and each letter designates a separate star or cartridge. Bracketed stars are a pair of different colors, discharged together from two pistols. The system is based on the Army and Navy Code, red representing "1" and green "2."