I ain't white but I won't hold it against the cultural norms of a time period, as to what were the normally accepted terms at the time. I still remember at school being asked to fill out forms asking what my "Christian" name was.

I don't mind filling out demographic race census type questionnaires, some of which can be rather amusing.

I have already warned my children about those questionnaires and to not feel offended when they have to tick 'other'.

I tick "other" in such surveys or censuses. I'm not at all comfortable with the idea that "white British" people have enough in common for that to be a useful classification. I don't expect all brown British people to have anything in common and see nothing but potential harm in lumping people together in this manner.

I think the census question (approximately) "what language did you first learn which you still speak?" provides enough demographic information for practical purposes.

If a Gov't census or questionnaire is anonymous why not try to be accurate.....anything else will simply skew the results and consequently their intent.

What useful intent can be served by knowing how many people think they are white?

I have no idea but, in a democracy, we vote for a gov't and comply with what they think is necessary....or demand answers from our representatives.

Taking matters into one's own hands, based on a personal belief, and attempting to destroy even a nebulous census is akin to anarchy.

Because if you dispute the premise of the question, what one person deems 'accurate' is not what another does.

You might think I could accurately answer a description 'White British', based on family background, birth location, etc. I've always been deeply uncomfortable with that subset (for reasons others have alluded to above), and checked the far more accurate 'Other - European'.

If everyone had done that I wonder if there'd have been a referendum

If you answered the question as accurately as you believed then you complied. If you did it knowing there was a more accurate answer..... then you didn't.

Which is necessarily at odds with your earlier claim (that answering how you wanted to, instead of divining the intent of the question masters, destroyed the reliability of the data).

Not at all...they ask very simple questions that don't require analyzing. A census requires simple answers to the best of one's knowledge.

This is different to those who arbitrarily choose to give a different answer to the one they know is accurate and consequently skew the results.

Hopefully there is a margin of errors that will tend to nullify those that wish to waste taxpayer's money.

Wooowww.. with a name like Cyan, you ain't blue are you? Never met a blue before...

Been to Australia...lotsa Blueys there....
https://www.urbandictionary.com/define.php?term=bluey

I always tick the option
"I prefer not to answer"

The Bureau for Racial Classification has not tracked me down yet.