Ballast fuel
Hello Paul.
My name is Luiz, I'm a brazilian Flight Dispatcher. Just complementing your question, at the Airline I work, we used to dispatch our B727-200F using ballast fuel procedures, when there is no weight (no pallets) on board. This value of "ballast fuel" is computed as cargo, it does not considered to be used during the flight. It appears on the output format of the flight planning (at block fuel) but this value is added to ZFW as cargo. As I have said, we using to dispatch our B727-200F with ballast fuel, only when we don't have any weight on board, nor on maideck nor in the holds.
I don't know if you understood what I meant.
Regards.
Luiz.