The Australian state of New South Wales issued revenue stamps from 1865 to 1998.
This tax was to compensate farmers who had diseased cattle killed for health reasons.
These are rare since the overprint dissolves in water, so it is very difficult to remove them from their original document.
The first stamp duty revenues were issued in 1865 portraying Queen Victoria.
Until 1901, a number of sets were issued, all portraying Queen Victoria but with many different designs.
This tax was to compensate farmers whose pigs died or were destroyed by swine fever.
The first set consisted of five values ranging from 1s to 20s from the King Edward VII stamp duty issue overprinted.
Twenty nine values ranging from 1d to £5 were issued, and are most commonly found in mint condition.