Thanks for your replies.
I had seen a reference to the "source code" idea on another thread when I was searching. But I am not technically savvy enough to get that to work for me, if someone could provide details on exactly how to get this information it would be greatly appreciated.
Checking ITA is a good idea. But some of the lower priced Qantas fares don't seem to show up on ITA.
If I phone my local Qantas office will they be able to give me the class of a particular fare, even if it is an Internet only special ?