Originally Posted by christep
HKG-<N America>-<Australia>-... can never be a valid routing for a xONEn ticket (you start from TC3 (Asia + Australasia), so you can only re-enter it at the end). If you go HKG-<N America> the next continent (in the absence of any NA-Africa flights) must be Europe.
So, then, when someone suggested a routing from SYD-LHR, a couple of stops in Europe, and then later had a series of North America stops, they were proposing an invalid routing, right?