Was looking at ex-MPM RTW prices on EF this evening and saw something that I don't think I've ever seen before: DTEAM4/5/6 fares on Finnair (AY). The fare rules look like just like DONEx.

Anyone know why they've got this different name? And has anyone ever booked a RTW with AY? These fares are *substantially* cheaper than AA/BA/etc, even ex-JNB.