s-1 : admin office augmentee : support staff from another unit mp : military police skipper : slang for captain meritorious rank : early competitive promotion , gained from a selection board marine cadence : motivating marine corps running or marching songs roe : rules of engagement manifest : flight roster fitrep : fitness report evaluation system for marines above the rank of corporal mre : meals ready to eat ( field rations ) j-2 : senior intelligence officer in a joint staff ( multiple services ) j-3 : senior operations officer in a joint staff lance coolie : slang for lance corporal ( e-3 ) awol : absent without leave ( unauthorized absence for extended period ) garrison : a garrison is the permanent home of a unit .