As nobody answered this I'll simply add that somebody familiar with IATA terminology contacted me to say that the Delta's description clearly applies to the *first* flight coupon regardless of whether it is the trans-oceanic flight coupon or not. Had they wanted to describe the trans-oceanic flight coupon (and possibly any preceeding flight coupons) they should have specified it as such (something that some other airlines apparently do).

Of course explaining all this to somebody at DL is still a challenge at best......