The manual of arms of a firearm, as it is used today, is instructions in its handling, use, and maintenance.
History[]
In the past, the manual of arms was specifically about the handling and use of arms in formation. Elements of close order drill now taught in militaries of today were part of these manuals of arms and were used extensively in pre-1800 military tactics.
Today, it is sometimes used as a reference to general weapons handling; while most infantry tactics today rely on teamwork and formations, there are no orders given to load and fire individual weapons while in large formations; weapons are already loaded and firing takes place when the individual infantry unit makes contact with an enemy.