I was a little puzzled by that, I have quite a number of certs. and that is the first time I have seen the X or Y. Most say the married name followed by maiden surname, MS. On some of the death certs, Margaret's daughter for example, it says mother's name
Margaret Stewart
Subsequently McAleer
M.S. Campbell
Thank you for the explanation, although this branch on my tree is driving me out of my tree I have had a lot of help from this forum and I learn something new every time I read all the letters
Cathie