Surely there must be some sort of audit trail at the ONS to explain the reversal from birth sex to self-ID sex between early February and the 22nd? Who pushed through the change? And why?
Q.27, the new gender identity question talks about identity in relation to 'your sex registered at birth' - not even what is on your birth certificate (now) - so they have the necessary vocabulary embedded in the form already.
It is actually a really good phrase - so it seems daft not to just have reused it in the guidance.
Here's my attempt
Sex:
Male
Female
Guidance
Record your sex registered at birth.
Your personal census data will only be made public in 2121. Accurate data on biological sex helps government to plan and resource health services, screening, education etc for the whole population.
Q.27 is an optional question to record your gender identity. Answering Q. 27 helps government to plan and resource health services etc specifically for people whose gender identity is different to their sex registered at birth.
You may request a paper copy of the census if you wish to record a gender identity or sexual orientation but do not wish it to be known by other household members on 21st March.
Sure it can be improved on but it is not impossible...