There are three major reservation systems used by major airlines and travel agents (and many other used by specific airlines). Depending on who made your reservation, you will need to view it through the appropriate viewing system.
All three of these major systems provide a booking reference number that looks similar in format. It does not really matter what it starts with, its all about the system in which it is valid.
And it gets even more confusing when you have an itinerary that is booked in one system and includes flights that need to be visible in the specific airline's systems. In those cases, the necessary booking information is pushed from the system in which the reservation is made into the other systems, plus the details of the connecting flights either side (so the operating airline knows how and when you arrive and depart before and after their sectors).
These three major systems are:
Sabre: used by AA and some TA's such as Carson Waginlit
Amadeus: used by QF and BA
Galileo: used by TA's such as Amex Travel
If you see your booking in the QF FF web site under My Bookings, it will have a booking reference for Amadeus and can seen at
http://www.checkmytrip.com
If your booking is made in Sabre, you can see it at
http://www.virtuallythere.com and can even be pushed to AvantGo for Palm/PocketPC download.
If your booking is made in Galileo, then view it at
http://www.viewtrip.com
If you don't know in which system the reservation was made, just try all three and it should work with one. Sometimes the itinerary from the TA will include booking references for all the airlines used, and those specific flights (plus connections) will be seen under the relevant viewing tool above.