Army Doctrine Reference Publication (ADRP) 4-0 augments the sustainment doctrine established in Army Doctrine Publication (ADP) 4-0, Sustainment. This manual expands the discussion on the overarching guidance on sustainment in ADRP 3-0, Unified Land Operations. It constitutes the Army's view of how it supports prompt and sustained operations on land and sets the foundation for developing the other principles, tactics, techniques, and procedures detailed in subordinate doctrine publications. It also forms the basis for Army training and education system curricula. The principal audience for ADRP 4-0 is commanders, leaders, and staff. It is also applicable to civilian leadership of the Army. Commanders and staffs of Army headquarters serving as a joint task force or a multinational headquarters should also refer to applicable joint or multinational doctrine concerning the range of military operations as well as joint or multinational forces. Trainers and educators throughout the Army will also use this manual. ADRP 4-0 uses joint terms where applicable. Most terms with joint or Army definitions are in both the glossary and the text. Terms for which ADRP 4-0 is the proponent publication (the authority) have an asterisk in the glossary. Definitions for which ADRP 4-0 is the proponent publication are in boldfaced text. These terms and their definitions will be in the next revision of ADP 1-02. For other definitions in the text, the term is italicized and the number of the proponent publication follows the definition. ADRP 4-0 applies to the Active Army, Army National Guard (ARNG)/Army National Guard of the United States (ARNGUS), and United States Army Reserve (USAR) unless otherwise stated. U.S. Army Combined Arms Support Command (CASCOM) is the proponent for this publication. The preparing agency is the Doctrine Division, U.S. Army Combined Arms Support Command