GEDCOM
GEDCOM is a genealogical data format developed by the FamilySearch Department of the Church of Jesus Christ of Latter Day Saints (the Mormons). The first version of the GEDCOM specification was released in 1984, and it was last updated in 2019 (version 5.5.5[1], supplemented with errata sheet). GEDCOM version 7 was released in 2021.
While it was for a long time the de-facto standard for electronic genealogical data, supported for import and export by most family-tree programs, progress has stagnated, with the standard not being updated in over a decade and many implementations not even providing complete support for the 1996 version (for instance, while GEDCOM 5.5 included UTF-8 support for Unicode-based internationalized character sets, useful for expressing names of people and places in their native form, some implementations are still using the much clunkier ANSEL character set format supported by earlier GEDCOM versions).
File Identification
Gedcom files are ASCII text which begin with "0 HEAD". Later versions have byte order mark at beginning indicating unicode.
Gedcom files can also be segmented to span multiple disks. .g00, .g01, .g02, etc
Detecting the different versions can be found here: GEDCOM Versions
Included in the GEDCOM 7 specification is the addition of the GEDZIP format to carry the GEDCOM and any multimedia content for sharing and archiving. Based on ZIP and uses the extension GDZ.[2]
