CDX47
Found this coupon code on Australian Frequent Flyer and should work for Economy Choice, Economy Flex and Business Class Fares on all domestic flights. I believe there is a 21-day advance purchase requirement (same as previous coupon code ITX13), and some blackout dates may apply. There is no listed end date for this code yet as far as I'm aware.
There is no option to enter a promo code at checkout so make sure you put it in when you're selecting the flight search settings (on the 3rd step).