Hi I am looking to fly from London via Asia through to Sydney next month and wanted to know how Qantas might be on a BA code shared flight in regards to cabin baggage allowance. I've been typically flying British Airways flights to Singapore/Hong Kong/Bangkok and then swapping to a Qantas flight mid-transit to get all the way back to Sydney. Now as i've been changing flights in transit i've never had my hand luggage re-weighed as i was never checking back in. For me this is really important as even though I have a BA approved 'regulation size' carry on bag the weight I bring exceeds what Qantas would typically allow. As a result i've always booked these flights via BA as they are the only airline I know of with no weight restrictions on carry-on bags, only size restrictions. This time on my flight back home though i'm thinking of doing a stop-over via Singapore or Hong Kong for a few days and I noticed that all flights back to Sydney from these places involved checking in for a Qantas / Cathay Pacific BA code shared flight from those places. So I was wondering would Qantas/Cathay enforce their own cabin baggage allowances over BA's allowances there when I check back in for the next leg of the flight back to Oz or would they actually allow the same limitations that BA allows there (size restricted only). PS. The reason I require this is I travel with a lot of computer and photography equipment which would be damaged if it got put into the hold.