NEW ZEALAND MT COOK 5/- STAMPS
Due to its high value, there was little genuine postal demand for the 5/- value, therefore the majority were fiscally used
Therefore collectors must be wary about cleaned fiscals, especially those that had a pen cancel. Some are offered unused while others have had a fake postmark applied.

Some stamps used fiscally have a punched hole.
Some fiscal cancellations look very like ordinary postmarks although any cancellation containing a crown is a fiscal cancel. The above illustrated stamp has a Crown cancel, it was fiscally used in Otago.
Embossing
Fiscal stamps were often cancelled by being embossed with a fernleaf pattern as well as being cancelled by a conventional datestamp. The example above is embossed with an additional Wellington cancel.
The Stamp below was Genuinely Postally used at Eltham
A Clean and Fresh Example with Crisp & Clear CDS "ELTHAM 10.AM 27 OC 10 N.Z