There was also a War Tax applied to perfume, sparkling wine, and patent medicines.
This meant that larger denominations were needed, and so a small number of 5c, 20c, and 50c,
were overprinted "WAR TAX" for use as Revenue stamps. Some were used to pay the regular postal War Tax on large parcels and so to prevent confusion the words "INLAND REVENUE"
were added to the overprint.
The usage of these stamps was limited in time as special Revenue Stamps were soon available.

Lower Plate 5.

Lower Plate 6.

Upper right Plate 9.

Upper right Plate 10.

Upper right Plate 6 with PO 185 and 216.

Lower Plate 2.

Lower Plate 3.

Upper plate 2 with PO 197.

Upper Plate 3.

Upper Plate 1 with PO 88.

Upper Plate 1 with PO 88 and 391.

Upper Plate 1 with PO 88 taken out.