St Catherines Index
St Catherine's Index (or the "St Cath's") is a widely-used (but now inaccurate) name for the index of births, deaths and marriages for England and Wales.
The name came into use when the General Records Office was housed in St Catherine's House, but it later moved to another location.
The indexes were created on a quarterly basis (that is, cover registrations for a three month period). Therefore a search for an entry for an unknown date could be extremely tedious. This motivated the FreeBMD project to create an online searchable index.