A planetary defence force, or PDF, is an organizational unit of the various governments and militaries of the Terran Sphere. A typical PDF recruits from the inhabitants of the host world and serves as a garrison. Although an equivalent to this terminology may or may not be in use in other spheres, many Terrans still apply it to various military units stationed on any world, regardless of the culture.
Alien PDF Organizations
Federation of Antillia
A PDF is not completely exclusive to Terrans however, as many other nations and spheres use them in defense of their territory. For example, in the Mandonian Sphere, and by default the Federation of Antillia utilizes the concept of a Planetary Defence Force, because of it's massive size and territory. Thus, like the Antillian government, a central authority for military command would be impossible, so the more "central" mobile Battlegroups with professional, well trained soldiers are moved where and when needed to supplement the local forces. The Colonial Peoples' Council, who run a colony, manage recruitment and pay for local land forces, where as Sector Peoples' Councils manage local spaceship and space-bound defence, such as sensor stations, military space stations and shipyards.
In a Military situation a Battlegroup with a Theater Command Council is dispatched to organize the PDF units in the area, in some cases a planet, system or entire sector and react accordingly with appropriate force.