The entries for the bride and groom will always have the same index reference number, so if you know the names of both parties you can cross-reference to ensure you have found the right marriage. The General Register Office's indexes give only the basic details of a marriage: name, the surname of the spouse (only from March 1912), the registration district and a reference number (volume and page). Marriage certificates are a rich source of family information that directly link one generation to another.