Purpose War Instructions 1944, derived from experience, is issued to indoctrinate officers in a common concept of naval combat warfare, and fighting procedures. Acceptance and understanding of these basic principles reduces the necessity for detailed instructions in orders. Scope War Instructions 1944 defines the doctrine of command, operation of ships and fleets, and encounters with the enemy. All paragraphs assume that there is a state of war or armed resistance, actual or probable. Amplification of this doctrine, with application to specific circumstances, is found in Navy Regulations, General Tactical Instructions, Current Tactical Orders and Doctrine U.S. Fleet, and other appropriate publications. The publication Joint Action of the Army and Navy defines the assigned common mission of the Army and Navy, the general functions of the two services, and the demarcation between them. The Joint Chiefs of Staff may establish specific joint functions and command relationships by addition to or modification of the general directives of the above publication. Applicability War Instructions 1944 do not limit in any respect the authority of a fleet or force commander to issue supplementary instructions or to suspend within his command the provisions of any paragraph. in the absence of such modifications, lower echelon commanders are governed by the instructions contained herein.