Like all databases, the IGI (LDS abbreviation for International Genealogical Index) and the Ancestral File should be used with caution. They should be considered secondary evidence (or maybe only hearsay) and should be checked against primary records. I know this is heresy in some quarters, but experience leads me to question the information. It should be used as guidelines only. Generally, if you are seeking British records and there is a C or an M before a number, which number is the probable source, then this information has been taken from largely parish records in England. All published information should be checked against primary records. Otherwise, it should be considered secondary or hearsay. Most of us doing US research start out with census records, and then we try to study other records which were made at the time the person was alive. Court records and land records are generally fairly reliable. Vital records were not kept in the South, with some exceptions, until very late (genealogically speaking). E.W.Wallace southern California