Zero Fuel Weight
Cessna 310.
Load up the aircraft in fuselage and nose up to max ZFW. Fuel can then be uploaded in Tips, aux and wing locker tanks if fitted.
If you did not have wing locker fuel tanks, but had the wing lockers as baggage compartments instead, it would be possible to load up the wing lockers with baggage up to the weight of fuel that they would have contained.
This makes sense structurally, as the airframe will only see the weight, not what is in the lockers.....but would a CAA/FAA inspector see it in the same light, or would the baggage in the wing lockers have to be included in the ZFW?