If you are or will be serving (especially for the first time) in a higher headquarters-such as service component command, combatant command, service staff, or joint staff-it is likely that you will be assigned to or collaborating with something called a commander's action group (CAG). These are also known as commander's initiatives groups, commander's special studies groups, or typical assistants groups. If you are assigned to one, you may carry the duty title of special assistant (SA), and your duty description will likely be broad and vague. Additionally, if you are like most first-timers in a CAG, you probably will have heard little to nothing about them in prior assignments.