The International Genealogical Index consists of two general types of records:
- Extracted vital records (births, christenings, marriages, and occasionally deaths). Transcriptions of vital records microfilmed and archived by LDS. These records are linked to the source in the FHL catalog from which they were transcribed. They have batch and film numbers, which themselves can be searched to find other records in the same group (i.e. search for all those with a particular last name baptized in a particular place). Batch numbers are specific to both event and source (marriages and christenings from the same source will have similar, but not identical, batch numbers)
- User-submitted records. User-submitted records, generally in connection with LDS requirements for documenting ancestry or sealing relationships. These records carry no source, and, while they are supposed to be supported by sources, are not necessarily reliable.
The IGI is a repository only for the extracted records, not the user-submitted records. For the user-submitted records, cite the IGI as the source.
When searching the IGI, the extracted records generally show up with the name in all capital letters, using the historical spelling, and a full, correct place name. This will often distinguish the record from user-submitted records using mixed case and location abbreviations.
The IGI used to be searched on a set of CDs available at most local FHCs, but has been available online since 1999.