A Genealogist's Glossary: GEDCOM Terms Without the Jargon

GEDCOM's terminology is precise but rarely explained in plain language anywhere you'd actually encounter it — an error message, a forum post, a program's settings menu. This glossary covers the terms most likely to show up when something isn't working.

Structure terms

GEDCOM — GEnealogical Data COMmunication, the standard file format genealogy software uses to exchange family tree data between programs.

Level, tag, value — the three-part pattern every line in a GEDCOM file follows: a nesting number, a fixed code describing the data, and the actual content. See Understanding GEDCOM's Level/Tag/Value Structure for a full walkthrough with examples.

Pointer — a reference from one record to another, written as an identifier inside @ symbols, like @I42@. Individual and family records reference each other by pointer rather than by containing each other's full data.

FAMC / FAMS — the two family-relationship tags on an individual record. FAMC ("family as child") points to the family a person was born into; FAMS ("family as spouse") points to a family they formed as a parent or spouse. These are the links a tool follows to trace ancestors or descendants.

Dangling reference — a pointer that references a record which doesn't actually exist in the file, usually caused by a previous edit, export, or partial file transfer that deleted the target record but left the reference behind. See Common GEDCOM Upload Error Messages, Explained for how this typically surfaces.

HEAD / TRLR — the required header (HEAD) and trailer (TRLR) records that open and close every valid GEDCOM file. The header declares the file's GEDCOM version and character encoding among other things.

Version and format terms

GEDCOM 5.5.1 — the long-standing version of the format used by most genealogy software for over two decades before GEDCOM 7.0's release. See GEDCOM 5.5.1 vs. 7.0: What Actually Changed for the specific differences.

GEDCOM 7.0 — the current major revision, finalized in 2021, requiring UTF-8 encoding and introducing more rigorously structured citations, among other changes. Software support is still uneven — see Does My Genealogy Software Support GEDCOM 7.0?.

GEDZIP — a container format introduced with GEDCOM 7.0 that bundles the GEDCOM data and its referenced media files into a single zip package, so photos and documents travel with the tree instead of being left behind. Full explanation in What Is GEDZIP, and Why Does It Matter for Photos?

Encoding terms

Character encoding — the rule a file uses to translate stored bytes into displayed characters. A GEDCOM file declares its encoding in its header; a mismatch between the declared encoding and how a program reads it is the direct cause of garbled names.

ANSEL — an older character encoding common in genealogy software from the 1990s and 2000s, built to handle accented and special characters using a different technical approach than modern Unicode. Full explanation in ANSEL Encoding Explained.

UTF-8 — the character encoding required by GEDCOM 7.0 and the safest universal choice for 5.5.1 files as well, since it's supported consistently across current genealogy software and by FamilySearch.

Date terms

Date qualifier — a prefix like ABT, BEF, AFT, or BET ... AND ... that expresses how certain or approximate a date is, rather than forcing every date to look equally exact. Every qualifier explained in How GEDCOM Dates Work.

Where to see these applied

Reading raw GEDCOM isn't something most people need to do routinely — the Upload Readiness Checker parses a file's structure, encoding, and version for you and reports on it in plain language. This glossary is here for the moments a raw error message or an unfamiliar term shows up and you want to know exactly what it's referring to.