I’ve got a couple of very dodgy certificates. The first is a death certificate where the lodger was the informant and was five years out with the age. That caused a brick wall which was finally resolved by a DNA test. The second is my great-grandfather’s birth certificate. Apparently he was rather proud of the fact that he had more birthdays than the king - his real one, the date on his baptism and the date given on his birth certificate, made up to avoid the fine for late registration.