A couple of recent threads have raised the issue of inter-continental transitions and someone asked for a clarification. Here is a brief summary of the required and possible inter-continent transitions. It repeats the sticky in a slightly different way.

All ONE tickets must make the three inter-area transitions, going consistently East (Areas 1-2-3-1) or West (Areas 3-2-1-3):
Area 1 (NA, SA) – Area 2 (EU, AF): the trans-Atlantic flight
Area 2 – Area 3 (AS, SW): the cross-Asia (or trans-Indian ocean) flight
Area 3- Area 1: the trans-Pacific flight (except for special case shown below)

Transitions that can be done as a direct- single segment:
Area 1-Area 2: NA-EU, SA-EU
Area 2- Area 3: AF-AS, AF-SW, EU-AS
Area 3- Area 1: AS-NA, SW-NA, SW-SA

Transitions that require an indirect but single segment (has a touch down which counts as continent):
Area 2- Area 3: EU-SW (thru AS)
Area 3- Area 1: AS-SA (thru NA- only JL47/48 otherwise need two segments)

Transition that involves an indirect, single segment (but with fly-over which counts as a continent)
Area 3- Area 1: special case DEL-ORD which counts as trans-Atlantic and adds EU

Transitions that require indirect flights- two segments necessary:
Area 1- Area 2: NA-AF through EU and SA-AF through EU.

If I have something wrong or incomplete, please correct or augment.