I've only ever heard the term wing tank or center tank (FCOM, Boeing fuel system data and ATM's). I'm not disputing the fact that the center-wing tank term is used in the industry also.
However, every day's an education
Anyway, we're diverging from the original post and I feel that I've unfairly hijacked it....
Edited to say that I've just looked at the 777 maintenance manual and the correct description is of the
center tank being in the "center-wing section". No reference to the center-wing tank - just main tanks, and center. Pheeew!
