LI - I call it Loading Index, but nobody trained me.
LI LAW: LAnding Weight
LI ZFW: Zero Fuel Weight
LI TOW: Take Off Weight.
The term Weight is being used with tolerance and respect to the previous generations, instead of correct "Mass". LAM, ZFM, TOM would be the same thing in this field, properly named.
Google harder.
1) 20.18 v.s. 20.18 is purely a coincidence, there is no co-relation.
2) significant fuel load forward of centre
3) units, no definition.