I had a shocking surprise when I bocked my first fligth involving different unused ST carriers (each one with its own code) and different zones* and stop overs.

*With different zones I mean zones where there's a specific baggage allowance.

Quite cerebral and I haev difficulties to explain, an example can explain better.
All in the hightest class (First for AF, Biz/First for CO, Biz for KLM and NW, Economy for AZ domestic)

Unique ticket:
HOU-CDG (AF) connecting with CDG-VCE (AF)
stop over
VCE-FCO (AZ)
stop over
FCO-AMS (KL) connecting with AMS-NRT (KL)
stop over
NRT-HNL (NW)
stop over
HNL-HOU (CO)

Max allowance
2 pieces of 32 kg each for USA-EU for AF
20 kg for a domestic fligth in Italy
30 kg for EU-Japan with KLM
2 pieces of 32 kg each plus an extra one of 18 kg for Japan-USA with NW
3 pieces of 32 kg with CO

So, to avoid paing any penality, you need to have only 20 Kg. The lowest limit. Each of the mentioend carriers has no visibility it's part of a more complex routing with different baggae allowance.
Remove the stop over in Rome (FCO), so you remove the 20 kg bottleneck with a VCE-AMS with KLM and you are limited by KLM with 30 Kg. If you are in connection, like CDG-VCE, you avoid the problem but it's not a viable answer.

Looks like a RTW itinerary... Is there a particular reason you are not bying a RTW ticket (which would at least allow you the piece concept in all flights)?

The example I provided, is just that, an example. The same I was 'kindly' provided to explain to a dummy guy (me) a simple concept (simple for an airline to get more money in baggage allowance) after too many calls with the ticket department of a few ST airlines.

I'm on an RTW (award, not revenue, if that makes a difference.) KE enforced the 30kg+18kg carryon when I started on my SYD-ICN-NRT and then inter-Asia segments. AF has told me they will be enforcing 30kg+12kg. SU has said 30kg for checked. This is a DL-ticketed flight originating and terminating in BOS. KE did give me the proper allowance LAX-ICN-AKL.

This is especially annoying because the way my luggage is configured, it forces me to have one large, heavy 30kg bag, then an underpacked max-sized carryon (with my camera backpack stuck in it as well) and laptop bag. I much prefer splitting the weight between the two rollerboards then just having my camera backpack and laptop bag to carry on... Doesn't make the plane any heavier (and puts a lot less weight in the overheads.)

So anyways, it does not seem that an RTW gives you your "home" baggage allowance the entire route...

Really, KE's US-Asia allownace is 32KG PER CHECKED BAG plus 12 KG CARRYON. Not 18KG.

I was travelling in J. The carryon limit for J/F is 2 pieces at 18kg total, vs 1 piece+1 personal item at 12kg total for Y. For checked bags US-Asia you also seem to get a slightly higher dimensional allowance (158cm total per bag in F/J, vs 273cm total for both bags in Y), though still the same 2x32kg. Anywhere else in the world, of course, is the standard 20kg/30kg/40kg for Y/J/F. (Even SYD-ICN-NRT: the "Transpacific Region" note on the website is misleading; any chance you could mention this to someone who might be able to clear up the wording?)

For what it's worth, Air France didn't give me any problems taking my ~5kg camera backpack and ~5kg laptop bag aboard intra-European flights, despite stating "1 piece maximum" with no mention of personal items. I was kinda worried there not having flown them before, and seeing very few people with the usual personal items you see elsewhere.

Officially, you can always have one personal item, such as a laptop, in addition to your one piece of cabin luggage with AF (except for small regional aircrafts where you may need to gate check some items). Never had a problem with that over the last ten years of flying with AF, mostly intra-European, even in Y.

[QUOTE=karthik]I was travelling in J. The carryon limit for J/F is 2 pieces at 18kg total, vs 1 piece+1 personal item at 12kg total for Y. For checked bags US-Asia you also seem to get a slightly higher dimensional allowance (158cm total per bag in F/J, vs 273cm total for both bags in Y), though still the same 2x32kg. Anywhere else in the world, of course, is the standard 20kg/30kg/40kg for Y/J/F. (Even SYD-ICN-NRT: the "Transpacific Region" note on the website is misleading; any chance you could mention this to someone who might be able to clear up the wording?)

Oh yeah, technically the carry-on luggage should be 18 kg TOTAL but at least at ORD the only carryon we usually ask the pax to place on the scale is the main bigger item and see if it is over 12 or below. I guess this depends on each airport station but at out station if the bigger item below 12kg and the other one doesn't seem too bad, we never really ask the pax for the second item.