Continental order in RTWs
 

This seems like such a basic question :o, but my searches haven't turned up the answer.

In a RTW itinerary involving both N and S America, is S America considered to be "east" of N America? To put it another way, in a westbound RTW must you do S America first, followed by N America, or doesn't it matter?

Similarly, is Africa "east" / "west" / neither of Europe & Middle East?

Without delving into the rules, it shouldn't matter. AFAIR, for the xONEy fares, it is possible to travel into Nth America, down to Sth America, then back up to Nth America and onwards (if one is a transit).

This link:
http://www.christen.demon.co.uk/CXRule/
has rules ex HKG.

The "circle" to go round world can zig-zag all over the place especially within continents. Eg: SYD-JFK-LAX-LHR is permitted in One World Explorer fares (xONEy).

My understanding was there's basically three zones - North and South America, Europe and Africa, and finally Asia and SW Pacific. So as OG has already said, it doesn't matter which order the continents are done, apart from making sure you match the zones (so you couldn't fly SYD-JHB-HKG, but SYD-HKG-JHB or HKG-SYD-JHB are both fine).

Within the zones and continent restrictions, anything goes. So for instance, you could fly MAD-SCL-IPC-SCL-NYC if you wanted to wander to the extremes of the zones and still stay legal (and I'm sure you could stretch things much further than this too :D ). No doubt others can clarify on my late night ramblings, but hopefully you get the basic gist of things :)

From that rules link : "Travel must be in a continuous forward direction between TC1-TC2-TC3." If TC* are the zones described by GibSpmuh, then at last I get it!

As I said, this seems such a basic question from somebody who has just completed an AONE4 (and is already thinking about future OWEs ;)), but I thought the forward progression rule applied at the level of the six continental zones.

Hmmm, this is even better than I thought :)

You can do SA at the beginning or end of your journey thru NA.