JP 3-0, page 56

Chapter III III-4 JP 3-0 (1) COCOM is the nontransferable command authority established by Title 10, United States Code (USC), Section 164, exercised only by commanders of unified or specified CCMDs unless otherwise directed by the President or SecDef. COCOM, which cannot be delegated, is the authority of a CCDR to perform those functions of command over assigned forces involving organizing and employing commands and forces, assigning tasks, designating objectives, and giving authoritative direction over all aspects of military operations, joint training, and logistics necessary to accomplish the missions assigned to the command. COCOM should be exercised through the commanders of subordinate organizations. Normally this authority is exercised through subordinate JFCs and Service and/or functional component commanders. COCOM provides full authority to organize and employ commands and forces as the CCDR considers necessary to accomplish assigned missions. In crisis response and combat, or where critical situations require changing the normal logistic process, the CCDRs’ logistic authority enables them to use all logistic capabilities of all forces assigned and attached to their commands as necessary to accomplish their mission. Under peacetime conditions, the CCDR will exercise logistic authority consistent with the peacetime limitations imposed by legislation, DOD policy or regulations, budgetary considerations, local conditions, and other specific conditions prescribed by SecDef or CJCS. (2) Operational control is inherent in COCOM and may be delegated within the command. OPCON is command authority that may be exercised by commanders at any echelon at or below the level of CCMD to perform those functions of command over subordinate forces involving organizing and employing commands and forces, assigning tasks, designating objectives, and giving authoritative direction necessary to accomplish the mission. OPCON includes authoritative direction over all aspects of military operations and joint training necessary to accomplish missions assigned to the command. This authority should be exercised through the commanders of subordinate organizations, normally through subordinate JFCs and Service and/or functional component commanders. OPCON normally provides full authority to organize commands and forces and to employ those forces as the commander in operational control considers necessary to accomplish assigned missions; it does not, in and of itself, include authoritative direction for logistics or matters of administration, discipline, internal organization, or unit training. (3) Tactical control is inherent in OPCON. TACON is command authority over assigned or attached forces or commands, or military capability or forces made available for tasking, that is limited to the detailed direction and control of movements or maneuvers within the operational area necessary to accomplish missions or tasks assigned. TACON may be delegated to, and exercised at any level at or below the level of CCMD. TACON provides sufficient authority for controlling and directing the application of force or tactical use of combat support assets within the assigned mission or task. Commanders may delegate TACON to subordinate commanders at any echelon at or below CCMD and may exercise TACON over assigned or attached forces or military capabilities or forces made available for tasking. TACON does not provide organizational authority or authoritative direction for administrative and logistic support or discipline (Uniform Code of Military Justice authority); the commander of the parent unit continues to exercise those responsibilities unless the establishing directive specifies otherwise. Except for special operations forces