Australia Annual Portfolio issue. This is the second of the Portfolio series with two of the $20 notes issued in a hard cover folder with matching serial numbers. Both numbers are also printed in red. This is the only paper Australia $20 banknote that printed with 2 letters prefix as all normal paper notes were printed with 3 letters prefix since 1966. The serial numbers range printed are from AA94 000 101 to AA94 001 000. However only 900 sets were released at $350 per set. The remaining 100 sets were retained by the central bank.