The same system operated in England and Wales and there are many "missing" entries in the central indexes due to compounded clerical errors. Also concerning the Irish immigrants who were illiterate...the Registrar wrote what HE thought was the name so many Mc surnames like mine have some curious spellings in the index. It took me three months to locate my paternal grandfather's birth certificate and I have now a fine collection of weird spellings on my paternal ancestor's certs and census returns.....i also checked the RC parish batismal registers and guess what.....there the surnames are correctly spelt...the priest was Irish and knew his parishoners well... It all is part of the fun of research...if it was too easy then we would soon be bored Regards Anton