Just for information, and an addition to my Rootsmagic question located at
https://community.rootsmagic.com/t/query-re-1939-uk-census-and-female-surnames/13709 about UK 1939 Census.
It just so happens the following was part of this month’s newsletter from lostcousins.com that I have received by email
https://www.lostcousins.com/newsletters2/inside1939v2.htm
This gives some more interesting information. Just like the preparedness by civil servants for war a year or 2 earlier than the invasion of Poland and WW2