The following abbreviations, conventional signals, and code calls are authorized in visual signaling:
ABBREVIATIONS.
| a | after. |
| b | before. |
| c | can. |
| h | have. |
| n | not. |
| r | are. |
| t | the. |
| u | you. |
| ur | your. |
| w | word. |
| wi | with. |
| y | yes. |
CODE CALLS.
| International Code use | ICU |
| (Navy) telegraph dictionary use | TDU |
| (Navy) geographical list use | GLU |
| (Navy) general signal use | GSU |
| Navy list use | NLU |
| Vessel's numbers use | VNU |
| Cipher "A" use[a] | CAU |
| Cipher "B" use[a] | CBU |
| Cipher "C" use[a] | CCU |
FOOTNOTE:
[a] These calls are for preconcerted use in or with the navy.
Although the use of but one alphabet is authorized in visual signaling in the U. S. Army, emergencies may arise where it may be imperative to use either the Army and Navy, the Continental Morse, or the American Morse alphabet. Instructions for the use of either alphabet under such conditions are given.