Sq Rtw
North American telephone sales people -- who are outsourced to India -- generally do not know about or understand these SQ RTW fares. You may have to argue with them to get them to even find the fare, much less get the rules straight. Or, work it through an SQ office or PPS desk.
In First, it's FEZSQ. No mileage limits or requirements; no minimum stay requirement; no minimum stopover requirement. NO backtracking: you cannot go through SIN to DPS, then back through SIN to SFO, for example.
Booking class is A: no good in Suites on the A380....