| Navy list | { | R | } | { | R | } |
| G | G |
| General call, rocket followed by G. | |
| Message call, G without the rocket. | |
The squadron, division, section, or ship's call, the "number" of | |
| Answering, or "I understand" | R |
| Repeating, or "I do not understand" | G |
| Danger or distress, R repeated several times in quick succession. |
ROCKET SIGNALING.
In general, rockets and shells are best used in displaying preconcerted signals.
Sequence rockets may also be used to display different colored lights in sequence to represent letters or numerals of the army and navy alphabet. The method of attaching the sections in the base of the sequence rocket is described in Chapter III. In using sequence rockets in this manner, the element "1" of the army and navy alphabet is represented by a red star, while a white star represents the element "2." To send the letter "A" a rocket showing two white stars is sent up. If "B" is to be sent, a rocket showing white-red-red-white is discharged. Each star burns for four to six seconds, and there is a slight interval between the visibility of each star. Between two or more stars of the same color, as "A," "N," "D," "dummies," which show no light and carry the fire to the next star to be ignited, are employed.
In the preparation of codes for signals with rockets or bombs there should always be arranged a "preparatory signal" which means "Are you ready?" etc., and an "answering signal," which means "Repeat your last signal," etc., a signal "annul," which means "Disregard last signal," and a signal to signify the correct receipt of the complete message, or "Signal seen and understood."
TWO-ARM SEMAPHORE ALPHABET, U. S. NAVY.