I will disagree somewhat with Callidus here – or at least, perhaps expand on ‘official forms’
The Heath, Education and Police sector all use ‘caucasian’ on at least some of their forms although, admittedly, ‘NZ Pakeha’ or ‘Pakeha’ or ‘New Zealand European’ is more common. I suspect that 'caucasian' on a form indicates that nobody has updated it in a while!
Lucky me, I had to spend a few hours in A&E 2 weeks ago and the admit and medical form specifically asked my ethnicity and race and again, mentioned caucasian. And, just to continue my story, last week I was punched and upon answering the answers on the police complaint form I was asked the ethnicity of my 'attacked'. Sure enough, ‘caucasian’ was an option. I might add, I actually identified the person as ‘Pakeha’ - presumably the cop filling out the form ticked caucasian. As a side note I should probably wrap myself in cotton wool.
However, OP - no it's not a particularly common term in New Zealand. The more common term here is New Zealand Pakeha or New Zealand European. I did a brief check and forms from our Social services department (WINZ) do refer to ethnicity rather than race.
I am not entirely sure if 'caucasian' is even used on census forms now or if it has shifted to more ethnicity related questions. For instance, elements of common culture, language, religion, customs rather than purely the race. It is the shift to more ethnicity based questions (and ethnicity based answers) which I think accounts for 'caucasian' being an uncommon term.
I shudder to think which common culture I belong to. Gen X Gen Y cusp of both, sauvignon in one hand, nokia in the other upward inflection kiwi perhaps.
Edited by: sneaker_fish