What is the meaning of special purpose Marine air-ground task force?

(DoD) A Marine air-ground task force organized, trained, and equipped with narrowly focused capabilities. It is designed to accomplish a specific mission, often of limited scope and duration. It may be any size, but normally it is a relatively small force--the size of a Marine expeditionary unit or smaller. Also called SPMAGTF. See also aviation combat element; combat service support element; command element; ground combat element; Marine air-ground task force; Marine expeditionary force; Marine expeditionary unit; task force.