"It is especially challenging to design a question when it involves a concept that may not be familiar to all."
Oh ffs it is not hard.
The question should have been "Are you trans?"
And all those foreign language respondents in Newham, that the article mentioned being confused, would not have been confused.
If you don't know what something means, you default to No. If you have never heard of the concept of transgender, you aren't transgender, so a default to No would be fine.
Who comes up with these census questions and why are they so devoid of common sense?!