[41.] The authorized [bugle signals] are published in [Part V] of these regulations.
The following bugle signals may be used off the battle field, when not likely to convey information to the enemy:
[Attention]: Troops are brought to attention.
[Attention to orders]: Troops fix their attention.
[Forward, march]: Used also to execute quick time from double time.
[Double time, march.]
[To the rear, march]: In close order, execute squads right about.
[Halt.]
[Assemble, march.]
The following bugle signals may be used on the battle field:
[Fix bayonets.]
[Charge.]
[Assemble, march.]
These signals are used only when intended for the entire firing line; hence they can be authorized only by the commander of a unit (for example, a regiment or brigade) which occupies a distinct section of the battle field. Exception: [Fix bayonet]. (See [par. 318].)
The following bugle signals are used in exceptional cases on the battle field. Their principal uses are in field exercises and practice firing.
[Commence firing]: Officers charged with fire direction and control open fire as soon as practicable. When given to a firing line, the signal is equivalent to fire at will.
[Cease firing]: All parts of the line execute cease firing at once.
These signals are not used by units smaller than a regiment, except when such unit is independent or detached from its regiment.