RootsChat.Com

Like all ethnicity predictions it seems a bit of a lottery.
On my father's side his paternal line is from Berks / Oxon and his maternal line is split between Sussex and  Jersey (Channel Islands). Ancestry only shows my community inherited from him as Berks / Oxon, no mention of any maternal contribution. I can understand that possibly these two further communities dilute the predictions
But, my mother's line is split between Dorset / Hampshire for her father and Yorkshire for her mother, but the only community that Ancestry shows for her side is Dorset / Hampshire. Again the paternal line only.

I have never  needed my long one for anything , driving licences, emigration , passport applications both ,  Aus and British ones, and  green cards in  Asia. I used my Short one on everything that needed a birth cert.
  The only one exception   that I  ever needed a long cert  was around 15 years ago , when I decided to send off  for  my 1st  Irish passport ( as my  Irish  citizenship  is through my  Irish  born  mother, I  needed my long cert to show my mum's name on it    unlike my British passport and my Aus  passports that didnt need my parents names on the cert).

need a full BC for most things now

https://www.gov.uk/apply-first-adult-passport/what-documents-you-need-to-apply


You were born or adopted in the UK
What documents you need depend on when you were born.

Before 1 January 1983
You’ll need your full birth certificate or adoption certificate.

"On or after 1 January 1983
You’ll need your full birth certificate or adoption certificate and either:

your mother’s or father’s full UK birth certificate, or the Home Office certificate of registration or naturalisation, or a British passport belonging to one of your parents that was valid when you were born, or a British passport number for either parent

evidence of one of your parents’ immigration status in the UK at the time of your birth, for example a foreign passport belonging to one of your parents that was valid when you were born

If you send documents relating to your father, you must also send your parents’ marriage certificate."

Ancestry also has the marriage records of the same  church - St Peters Derby - for the period. I have looked from 14 Feb 1841 (3rd Banns reading) until early march 1841. No sign of marriage so it must have been cancelled. They should both appear as single people on 1841 census.

After reading this thread, I had a look with what Ancestry have come up with for my ethnicity on their latest update. For the Central Southern England, it  has helpfully broken the communities down to:
Dorset to Greater London
Dorset, Hampshire & Surrounding Area
Oxfordshire & West Berkshire Area
Northeastern South West England & Northwestern South East England

Counties I understand, but how is Northeastern South West England & Northwestern South East England different to the other three regions

The Kennel club on DNA testing

https://www.thekennelclub.org.uk/health-and-dog-care/health/getting-started-with-health-testing-and-screening/dna-testing/#:~:text=Understanding%20your%20dog's%20genetics%20will,tests%20and%20treatments%20later%20on.