A320: unusable fuel in center tank.
Imagine that the 2 center tanks fuel pumps are inop and there's 1500 kg of fuel remaining in the center tank. According to MEL, you can depart with the 1500 kg in your center tank, but they must must be considered part of the ZFW. That part is clear.
Of course, one has to take the index shift into account for this fuel. The only location I can think of to find what the index shift will be, is on the back of our company's manual loadsheet. I'd look at what index I get with wings full + 1500 kg in the center and compare that to the "full wings index" The difference between the two is the number I need.
And now the question: Is there any other document that could give me the index change for 1500 kg unusable fuel in the center tank? Has Airbus published that?