fuel jettison limit weight
 

Any ideas what is fuel jettison limit weight? Is it a limited takeoff weight that assume that we have to dump fuel so we can attain the approach climb limited weight if we're returning to the departure airport?

Fuel jettison limit weight seems to be a fairly new addition - it popped up in the FCOM some ~2 years ago (at least on the 787).

As you guessed, it's a landing climb limited weight plus fuel burned over 30 minutes and fuel jettisoned over 15 minutes. So basically it is a takeoff limiting weight assuming the scenario that you turn back to the departure airport and land after 30 minutes, having dumped fuel for 15 minutes.

I don't know if it is some new certification requirement - haven't found anything in he EASA OPS rules. Perhaps it's somewhere in CS-25. Another thing I don't understand is that Boeing mentions ZFW as a factor here. The tables in the FCOM are based on maximum certified MZFW, however Mr. Boeing says that using lower ZFW may yield less restrictive performance...

EDIT: I have found an exhaustive paper on this new requirement by the FAA