My great, great, great grandmother was always known as Fanny. On her baptism, her name is spellt Phanny. I noticed that one of her father's sisters was also called Phanny. Only on her marriage certificate is she referred to as Frances, everywhere else such as on her children's baptisms and on censuses she is Fanny. On her death certificate there is an added note at the end where the registrar had assumed she was Frances, and in order to change her name from Frances to Fanny he had to call back the original Informant, her son-in-law, and also her daughter, to both put their marks against the change of name. It looks as though the registrar wasn't accepting the son-in-law's word for it and wanted the daughter to also sign that her mother's name was Fanny and not Frances.