- C2IEDM or C2IEDM (Command and Control Information Exchange Data Model)
- C2IP (Command and Control Initiatives Program)
- C2IPS (Command and Control Information Processing System)
- C2IS (Command and Control Information System)
- C2IS or C2IS (Command and Control Information System)
- C2MAA (Command and Control Mission Area Analysis)
- C2MADP (Command and Control Mission Area Development Plan)
- C2MAMP (Command and Control Mission Area Materiel Plan)
- C2MUG (Command and Control Microcomputer Users Group)
- C2 or C2 (Command and Control)
- C2P (Command and Control Planning)
- C2PC or C2PC (Command and Control Personal Computer)
- C2-Protect (Command and Control warfare - Defensive)
- C2S (Command and Control Support)
- C2S2 (Command, Control, and Subordinate Systems)
- C2SA-E (Command and Control Support Activity-Europe)
- C2SPR (Command and Control System Program Review)
- C2T2 (Close Combat Tactical Trainer)
- C2V (Command and Control Vehicle)
- C2V or C2V (Command and Control Vehicle)
- C2W (Command and Control Warfare)
- C2W or C2W (Command and Control Warfare)
- C-2X (Coalition Intelligence Directorate, Counter-intelligence and Human Intelligence Staff Element)
- C3 (propane)
- C3AG (Command, Control, and Communications Advisory Group)
- C3CM (Command, Control, and Communications Countermeasures)
- C3I (Command, control, communications, and intelligence)
- C3IC (Coalition Coordination, Communications, and Integration Center)
- C3IEW (Command, Control, Communications, Intelligence, and Electronic Warfare)
- C3I or C3I (Command, Control, Communications, and Intelligence)
- C3MP (Command, Control, and Communications Master Plan)
- C3 or C3 (Colorectal Cancer Condition||Command, Control, and Communications)
- C3S (Command, Control, and Communications Systems)
- C3SMP (Command, Control, and Communications Systems Master Plan)
- C4 (butane)
- C-4 (Composition C-4 plastic explosive)
- C4AH (Center for Advanced Hindsight)
- C4CM (Command, Control, Communications, and Computer Counter-Measures)
- C4D (Cinema 4D)
- C4I (Command, Control, Communications, Computers, and Intelligence)
- C4IFTW (Command, Control, Communications, Computers, and Intelligence For The Warrior)
